forked from lijiext/lammps
395 lines
16 KiB
Plaintext
395 lines
16 KiB
Plaintext
// **************************************************************************
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// dpd.cu
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// -------------------
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// Trung Dac Nguyen (ORNL)
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//
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// Device code for acceleration of the dpd pair style
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//
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// __________________________________________________________________________
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// This file is part of the LAMMPS Accelerator Library (LAMMPS_AL)
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// __________________________________________________________________________
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//
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// begin : Jan 15, 2014
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// email : nguyentd@ornl.gov
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// ***************************************************************************/
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#ifdef NV_KERNEL
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#include "lal_aux_fun1.h"
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#ifndef _DOUBLE_DOUBLE
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texture<float4> pos_tex;
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texture<float4> vel_tex;
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#else
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texture<int4,1> pos_tex;
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texture<int4,1> vel_tex;
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#endif
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#else
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#define pos_tex x_
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#define vel_tex v_
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#endif
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#define EPSILON (numtyp)1.0e-10
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//#define _USE_UNIFORM_SARU_LCG
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//#define _USE_UNIFORM_SARU_TEA8
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//#define _USE_GAUSSIAN_SARU_LCG
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#if !defined(_USE_UNIFORM_SARU_LCG) && !defined(_USE_UNIFORM_SARU_TEA8) && !defined(_USE_GAUSSIAN_SARU_LCG)
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#define _USE_UNIFORM_SARU_LCG
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#endif
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// References:
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// 1. Y. Afshar, F. Schmid, A. Pishevar, S. Worley, Comput. Phys. Comm. 184 (2013), 1119–1128.
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// 2. C. L. Phillips, J. A. Anderson, S. C. Glotzer, Comput. Phys. Comm. 230 (2011), 7191-7201.
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// PRNG period = 3666320093*2^32 ~ 2^64 ~ 10^19
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#define LCGA 0x4beb5d59 // Full period 32 bit LCG
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#define LCGC 0x2600e1f7
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#define oWeylPeriod 0xda879add // Prime period 3666320093
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#define oWeylOffset 0x8009d14b
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#define TWO_N32 0.232830643653869628906250e-9f /* 2^-32 */
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// specifically implemented for steps = 1; high = 1.0; low = -1.0
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// returns uniformly distributed random numbers u in [-1.0;1.0]
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// using the inherent LCG, then multiply u with sqrt(3) to "match"
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// with a normal random distribution.
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// Afshar et al. mutlplies u in [-0.5;0.5] with sqrt(12)
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// Curly brackets to make variables local to the scope.
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#ifdef _USE_UNIFORM_SARU_LCG
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#define SQRT3 (numtyp)1.7320508075688772935274463
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#define saru(seed1, seed2, seed, timestep, randnum) { \
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unsigned int seed3 = seed + timestep; \
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seed3^=(seed1<<7)^(seed2>>6); \
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seed2+=(seed1>>4)^(seed3>>15); \
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seed1^=(seed2<<9)+(seed3<<8); \
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seed3^=0xA5366B4D*((seed2>>11) ^ (seed1<<1)); \
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seed2+=0x72BE1579*((seed1<<4) ^ (seed3>>16)); \
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seed1^=0x3F38A6ED*((seed3>>5) ^ (((signed int)seed2)>>22)); \
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seed2+=seed1*seed3; \
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seed1+=seed3 ^ (seed2>>2); \
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seed2^=((signed int)seed2)>>17; \
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unsigned int state = 0x79dedea3*(seed1^(((signed int)seed1)>>14)); \
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unsigned int wstate = (state + seed2) ^ (((signed int)state)>>8); \
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state = state + (wstate*(wstate^0xdddf97f5)); \
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wstate = 0xABCB96F7 + (wstate>>1); \
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state = LCGA*state + LCGC; \
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wstate = wstate + oWeylOffset+((((signed int)wstate)>>31) & oWeylPeriod); \
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unsigned int v = (state ^ (state>>26)) + wstate; \
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unsigned int s = (signed int)((v^(v>>20))*0x6957f5a7); \
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randnum = SQRT3*(s*TWO_N32*(numtyp)2.0-(numtyp)1.0); \
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}
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#endif
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// specifically implemented for steps = 1; high = 1.0; low = -1.0
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// returns uniformly distributed random numbers u in [-1.0;1.0] using TEA8
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// then multiply u with sqrt(3) to "match" with a normal random distribution
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// Afshar et al. mutlplies u in [-0.5;0.5] with sqrt(12)
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#ifdef _USE_UNIFORM_SARU_TEA8
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#define SQRT3 (numtyp)1.7320508075688772935274463
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#define k0 0xA341316C
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#define k1 0xC8013EA4
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#define k2 0xAD90777D
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#define k3 0x7E95761E
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#define delta 0x9e3779b9
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#define rounds 8
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#define saru(seed1, seed2, seed, timestep, randnum) { \
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unsigned int seed3 = seed + timestep; \
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seed3^=(seed1<<7)^(seed2>>6); \
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seed2+=(seed1>>4)^(seed3>>15); \
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seed1^=(seed2<<9)+(seed3<<8); \
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seed3^=0xA5366B4D*((seed2>>11) ^ (seed1<<1)); \
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seed2+=0x72BE1579*((seed1<<4) ^ (seed3>>16)); \
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seed1^=0x3F38A6ED*((seed3>>5) ^ (((signed int)seed2)>>22)); \
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seed2+=seed1*seed3; \
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seed1+=seed3 ^ (seed2>>2); \
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seed2^=((signed int)seed2)>>17; \
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unsigned int state = 0x79dedea3*(seed1^(((signed int)seed1)>>14)); \
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unsigned int wstate = (state + seed2) ^ (((signed int)state)>>8); \
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state = state + (wstate*(wstate^0xdddf97f5)); \
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wstate = 0xABCB96F7 + (wstate>>1); \
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unsigned int sum = 0; \
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for (int i=0; i < rounds; i++) { \
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sum += delta; \
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state += ((wstate<<4) + k0)^(wstate + sum)^((wstate>>5) + k1); \
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wstate += ((state<<4) + k2)^(state + sum)^((state>>5) + k3); \
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} \
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unsigned int v = (state ^ (state>>26)) + wstate; \
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unsigned int s = (signed int)((v^(v>>20))*0x6957f5a7); \
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randnum = SQRT3*(s*TWO_N32*(numtyp)2.0-(numtyp)1.0); \
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}
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#endif
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// specifically implemented for steps = 1; high = 1.0; low = -1.0
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// returns two uniformly distributed random numbers r1 and r2 in [-1.0;1.0],
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// and uses the polar method (Marsaglia's) to transform to a normal random value
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// This is used to compared with CPU DPD using RandMars::gaussian()
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#ifdef _USE_GAUSSIAN_SARU_LCG
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#define saru(seed1, seed2, seed, timestep, randnum) { \
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unsigned int seed3 = seed + timestep; \
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seed3^=(seed1<<7)^(seed2>>6); \
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seed2+=(seed1>>4)^(seed3>>15); \
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seed1^=(seed2<<9)+(seed3<<8); \
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seed3^=0xA5366B4D*((seed2>>11) ^ (seed1<<1)); \
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seed2+=0x72BE1579*((seed1<<4) ^ (seed3>>16)); \
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seed1^=0x3F38A6ED*((seed3>>5) ^ (((signed int)seed2)>>22)); \
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seed2+=seed1*seed3; \
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seed1+=seed3 ^ (seed2>>2); \
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seed2^=((signed int)seed2)>>17; \
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unsigned int state=0x12345678; \
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unsigned int wstate=12345678; \
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state = 0x79dedea3*(seed1^(((signed int)seed1)>>14)); \
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wstate = (state + seed2) ^ (((signed int)state)>>8); \
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state = state + (wstate*(wstate^0xdddf97f5)); \
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wstate = 0xABCB96F7 + (wstate>>1); \
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unsigned int v, s; \
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numtyp r1, r2, rsq; \
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while (1) { \
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state = LCGA*state + LCGC; \
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wstate = wstate + oWeylOffset+((((signed int)wstate)>>31) & oWeylPeriod); \
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v = (state ^ (state>>26)) + wstate; \
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s = (signed int)((v^(v>>20))*0x6957f5a7); \
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r1 = s*TWO_N32*(numtyp)2.0-(numtyp)1.0; \
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state = LCGA*state + LCGC; \
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wstate = wstate + oWeylOffset+((((signed int)wstate)>>31) & oWeylPeriod); \
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v = (state ^ (state>>26)) + wstate; \
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s = (signed int)((v^(v>>20))*0x6957f5a7); \
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r2 = s*TWO_N32*(numtyp)2.0-(numtyp)1.0; \
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rsq = r1 * r1 + r2 * r2; \
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if (rsq < (numtyp)1.0) break; \
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} \
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numtyp fac = ucl_sqrt((numtyp)-2.0*log(rsq)/rsq); \
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randnum = r2*fac; \
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}
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#endif
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__kernel void k_dpd(const __global numtyp4 *restrict x_,
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const __global numtyp4 *restrict coeff,
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const int lj_types,
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const __global numtyp *restrict sp_lj,
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const __global int * dev_nbor,
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const __global int * dev_packed,
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__global acctyp4 *restrict ans,
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__global acctyp *restrict engv,
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const int eflag, const int vflag, const int inum,
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const int nbor_pitch,
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const __global numtyp4 *restrict v_,
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const __global numtyp *restrict cutsq,
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const numtyp dtinvsqrt, const int seed,
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const int timestep, const int tstat_only,
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const int t_per_atom) {
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int tid, ii, offset;
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atom_info(t_per_atom,ii,tid,offset);
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acctyp energy=(acctyp)0;
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acctyp4 f;
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f.x=(acctyp)0; f.y=(acctyp)0; f.z=(acctyp)0;
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acctyp virial[6];
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for (int i=0; i<6; i++)
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virial[i]=(acctyp)0;
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if (ii<inum) {
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int i, numj, nbor, nbor_end;
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__local int n_stride;
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nbor_info(dev_nbor,dev_packed,nbor_pitch,t_per_atom,ii,offset,i,numj,
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n_stride,nbor_end,nbor);
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numtyp4 ix; fetch4(ix,i,pos_tex); //x_[i];
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int itype=ix.w;
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numtyp4 iv; fetch4(iv,i,vel_tex); //v_[i];
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int itag=iv.w;
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numtyp factor_dpd;
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for ( ; nbor<nbor_end; nbor+=n_stride) {
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int j=dev_packed[nbor];
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factor_dpd = sp_lj[sbmask(j)];
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j &= NEIGHMASK;
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numtyp4 jx; fetch4(jx,j,pos_tex); //x_[j];
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int jtype=jx.w;
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numtyp4 jv; fetch4(jv,j,vel_tex); //v_[j];
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int jtag=jv.w;
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// Compute r12
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numtyp delx = ix.x-jx.x;
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numtyp dely = ix.y-jx.y;
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numtyp delz = ix.z-jx.z;
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numtyp rsq = delx*delx+dely*dely+delz*delz;
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int mtype=itype*lj_types+jtype;
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if (rsq<cutsq[mtype]) {
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numtyp r=ucl_sqrt(rsq);
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if (r < EPSILON) continue;
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numtyp rinv=ucl_recip(r);
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numtyp delvx = iv.x - jv.x;
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numtyp delvy = iv.y - jv.y;
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numtyp delvz = iv.z - jv.z;
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numtyp dot = delx*delvx + dely*delvy + delz*delvz;
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numtyp wd = (numtyp)1.0 - r/coeff[mtype].w;
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unsigned int tag1=itag, tag2=jtag;
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if (tag1 > tag2) {
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tag1 = jtag; tag2 = itag;
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}
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numtyp randnum = (numtyp)0.0;
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saru(tag1, tag2, seed, timestep, randnum);
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// conservative force = a0 * wd, or 0 if tstat only
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// drag force = -gamma * wd^2 * (delx dot delv) / r
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// random force = sigma * wd * rnd * dtinvsqrt;
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numtyp force = (numtyp)0.0;
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if (!tstat_only) force = coeff[mtype].x*wd;
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force -= coeff[mtype].y*wd*wd*dot*rinv;
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force += coeff[mtype].z*wd*randnum*dtinvsqrt;
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force*=factor_dpd*rinv;
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f.x+=delx*force;
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f.y+=dely*force;
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f.z+=delz*force;
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if (eflag>0) {
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// unshifted eng of conservative term:
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// evdwl = -a0[itype][jtype]*r * (1.0-0.5*r/cut[itype][jtype]);
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// eng shifted to 0.0 at cutoff
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numtyp e = (numtyp)0.5*coeff[mtype].x*coeff[mtype].w * wd*wd;
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energy+=factor_dpd*e;
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}
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if (vflag>0) {
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virial[0] += delx*delx*force;
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virial[1] += dely*dely*force;
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virial[2] += delz*delz*force;
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virial[3] += delx*dely*force;
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virial[4] += delx*delz*force;
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virial[5] += dely*delz*force;
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}
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}
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} // for nbor
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store_answers(f,energy,virial,ii,inum,tid,t_per_atom,offset,eflag,vflag,
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ans,engv);
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} // if ii
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}
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__kernel void k_dpd_fast(const __global numtyp4 *restrict x_,
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const __global numtyp4 *restrict coeff_in,
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const __global numtyp *restrict sp_lj_in,
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const __global int * dev_nbor,
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const __global int * dev_packed,
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__global acctyp4 *restrict ans,
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__global acctyp *restrict engv,
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const int eflag, const int vflag, const int inum,
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const int nbor_pitch,
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const __global numtyp4 *restrict v_,
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const __global numtyp *restrict cutsq,
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const numtyp dtinvsqrt, const int seed,
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const int timestep, const int tstat_only,
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const int t_per_atom) {
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int tid, ii, offset;
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atom_info(t_per_atom,ii,tid,offset);
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__local numtyp4 coeff[MAX_SHARED_TYPES*MAX_SHARED_TYPES];
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__local numtyp sp_lj[4];
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if (tid<4)
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sp_lj[tid]=sp_lj_in[tid];
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if (tid<MAX_SHARED_TYPES*MAX_SHARED_TYPES) {
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coeff[tid]=coeff_in[tid];
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}
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acctyp energy=(acctyp)0;
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acctyp4 f;
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f.x=(acctyp)0; f.y=(acctyp)0; f.z=(acctyp)0;
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acctyp virial[6];
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for (int i=0; i<6; i++)
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virial[i]=(acctyp)0;
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__syncthreads();
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if (ii<inum) {
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int i, numj, nbor, nbor_end;
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__local int n_stride;
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nbor_info(dev_nbor,dev_packed,nbor_pitch,t_per_atom,ii,offset,i,numj,
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n_stride,nbor_end,nbor);
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numtyp4 ix; fetch4(ix,i,pos_tex); //x_[i];
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int iw=ix.w;
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int itype=fast_mul((int)MAX_SHARED_TYPES,iw);
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numtyp4 iv; fetch4(iv,i,vel_tex); //v_[i];
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int itag=iv.w;
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numtyp factor_dpd;
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for ( ; nbor<nbor_end; nbor+=n_stride) {
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int j=dev_packed[nbor];
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factor_dpd = sp_lj[sbmask(j)];
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j &= NEIGHMASK;
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numtyp4 jx; fetch4(jx,j,pos_tex); //x_[j];
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int mtype=itype+jx.w;
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numtyp4 jv; fetch4(jv,j,vel_tex); //v_[j];
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int jtag=jv.w;
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// Compute r12
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numtyp delx = ix.x-jx.x;
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numtyp dely = ix.y-jx.y;
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numtyp delz = ix.z-jx.z;
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numtyp rsq = delx*delx+dely*dely+delz*delz;
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if (rsq<cutsq[mtype]) {
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numtyp r=ucl_sqrt(rsq);
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if (r < EPSILON) continue;
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numtyp rinv=ucl_recip(r);
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numtyp delvx = iv.x - jv.x;
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numtyp delvy = iv.y - jv.y;
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numtyp delvz = iv.z - jv.z;
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numtyp dot = delx*delvx + dely*delvy + delz*delvz;
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numtyp wd = (numtyp)1.0 - r/coeff[mtype].w;
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unsigned int tag1=itag, tag2=jtag;
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if (tag1 > tag2) {
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tag1 = jtag; tag2 = itag;
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}
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numtyp randnum = (numtyp)0.0;
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saru(tag1, tag2, seed, timestep, randnum);
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// conservative force = a0 * wd, or 0 if tstat only
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// drag force = -gamma * wd^2 * (delx dot delv) / r
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// random force = sigma * wd * rnd * dtinvsqrt;
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numtyp force = (numtyp)0.0;
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if (!tstat_only) force = coeff[mtype].x*wd;
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force -= coeff[mtype].y*wd*wd*dot*rinv;
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force += coeff[mtype].z*wd*randnum*dtinvsqrt;
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force*=factor_dpd*rinv;
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f.x+=delx*force;
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f.y+=dely*force;
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f.z+=delz*force;
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if (eflag>0) {
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// unshifted eng of conservative term:
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// evdwl = -a0[itype][jtype]*r * (1.0-0.5*r/cut[itype][jtype]);
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// eng shifted to 0.0 at cutoff
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numtyp e = (numtyp)0.5*coeff[mtype].x*coeff[mtype].w * wd*wd;
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energy+=factor_dpd*e;
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}
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if (vflag>0) {
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virial[0] += delx*delx*force;
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virial[1] += dely*dely*force;
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virial[2] += delz*delz*force;
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virial[3] += delx*dely*force;
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virial[4] += delx*delz*force;
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virial[5] += dely*delz*force;
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}
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}
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} // for nbor
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store_answers(f,energy,virial,ii,inum,tid,t_per_atom,offset,eflag,vflag,
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ans,engv);
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} // if ii
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}
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