Merge pull request #842 from martok/meamc-bugfix

MEAM/C Improvements/fixes

src/USER-MEAMC/meam.h

@@ -208,7 +208,6 @@ protected:
   void get_sijk(double, int, int, int, double*);
   void get_densref(double, int, int, double*, double*, double*, double*, double*, double*, double*, double*);
   void interpolate_meam(int);
-  double compute_phi(double, int, int);
 
 public:
   void meam_setup_global(int nelt, lattice_t* lat, double* z, int* ielement, double* atwt, double* alpha,
@@ -248,5 +247,13 @@ static inline void setall3d(TYPE (&arr)[maxi][maxj][maxk], const TYPE v) {
         arr[i][j][k] = v;
 }
 
+// Helper functions
+
+static inline double fdiv_zero(const double n, const double d) {
+  if (iszero(d))
+    return 0.0;
+  return n / d;
+}
+
 };
 #endif

src/USER-MEAMC/meam_dens_final.cpp

@@ -33,9 +33,9 @@ MEAM::meam_dens_final(int nlocal, int eflag_either, int eflag_global, int eflag_
 
       if (rho0[i] > 0.0) {
         if (this->ialloy == 1) {
-          t_ave[i][0] = (tsq_ave[i][0] != 0.0 ) ? t_ave[i][0] / tsq_ave[i][0] : 0.0;
+          t_ave[i][0] = fdiv_zero(t_ave[i][0], tsq_ave[i][0]);
-          t_ave[i][1] = (tsq_ave[i][1] != 0.0 ) ? t_ave[i][1] / tsq_ave[i][1] : 0.0;
+          t_ave[i][1] = fdiv_zero(t_ave[i][1], tsq_ave[i][1]);
-          t_ave[i][0] = (tsq_ave[i][2] != 0.0 ) ? t_ave[i][2] / tsq_ave[i][2] : 0.0;
+          t_ave[i][2] = fdiv_zero(t_ave[i][2], tsq_ave[i][2]);
         } else if (this->ialloy == 2) {
           t_ave[i][0] = this->t1_meam[elti];
           t_ave[i][1] = this->t2_meam[elti];

src/USER-MEAMC/meam_force.cpp

@@ -245,31 +245,19 @@ MEAM::meam_force(int i, int eflag_either, int eflag_global, int eflag_atom, int
 
         if (this->ialloy == 1) {
 
-          a1i = 0.0;
+          a1i = fdiv_zero(drhoa0j * sij, tsq_ave[i][0]);
-          a1j = 0.0;
+          a1j = fdiv_zero(drhoa0i * sij, tsq_ave[j][0]);
-          a2i = 0.0;
+          a2i = fdiv_zero(drhoa0j * sij, tsq_ave[i][1]);
-          a2j = 0.0;
+          a2j = fdiv_zero(drhoa0i * sij, tsq_ave[j][1]);
-          a3i = 0.0;
+          a3i = fdiv_zero(drhoa0j * sij, tsq_ave[i][2]);
-          a3j = 0.0;
+          a3j = fdiv_zero(drhoa0i * sij, tsq_ave[j][2]);
-          if (!iszero(tsq_ave[i][0]))
-            a1i = drhoa0j * sij / tsq_ave[i][0];
-          if (!iszero(tsq_ave[j][0]))
-            a1j = drhoa0i * sij / tsq_ave[j][0];
-          if (!iszero(tsq_ave[i][1]))
-            a2i = drhoa0j * sij / tsq_ave[i][1];
-          if (!iszero(tsq_ave[j][1]))
-            a2j = drhoa0i * sij / tsq_ave[j][1];
-          if (!iszero(tsq_ave[i][2]))
-            a3i = drhoa0j * sij / tsq_ave[i][2];
-          if (!iszero(tsq_ave[j][2]))
-            a3j = drhoa0i * sij / tsq_ave[j][2];
 
-          dt1dr1 = a1i * (t1mj - t1i * t1mj*t1mj);
+          dt1dr1 = a1i * (t1mj - t1i * MathSpecial::square(t1mj));
-          dt1dr2 = a1j * (t1mi - t1j * t1mi*t1mi);
+          dt1dr2 = a1j * (t1mi - t1j * MathSpecial::square(t1mi));
-          dt2dr1 = a2i * (t2mj - t2i * t2mj*t2mj);
+          dt2dr1 = a2i * (t2mj - t2i * MathSpecial::square(t2mj));
-          dt2dr2 = a2j * (t2mi - t2j * t2mi*t2mi);
+          dt2dr2 = a2j * (t2mi - t2j * MathSpecial::square(t2mi));
-          dt3dr1 = a3i * (t3mj - t3i * t3mj*t3mj);
+          dt3dr1 = a3i * (t3mj - t3i * MathSpecial::square(t3mj));
-          dt3dr2 = a3j * (t3mi - t3j * t3mi*t3mi);
+          dt3dr2 = a3j * (t3mi - t3j * MathSpecial::square(t3mi));
 
         } else if (this->ialloy == 2) {
 
@@ -331,32 +319,19 @@ MEAM::meam_force(int i, int eflag_either, int eflag_global, int eflag_atom, int
           drho3ds2 = a3 * rhoa3i * arg1j3 - a3a * rhoa3i * arg3j3;
 
           if (this->ialloy == 1) {
+            a1i = fdiv_zero(rhoa0j, tsq_ave[i][0]);
+            a1j = fdiv_zero(rhoa0i, tsq_ave[j][0]);
+            a2i = fdiv_zero(rhoa0j, tsq_ave[i][1]);
+            a2j = fdiv_zero(rhoa0i, tsq_ave[j][1]);
+            a3i = fdiv_zero(rhoa0j, tsq_ave[i][2]);
+            a3j = fdiv_zero(rhoa0i, tsq_ave[j][2]);
 
-            a1i = 0.0;
+            dt1ds1 = a1i * (t1mj - t1i * MathSpecial::square(t1mj));
-            a1j = 0.0;
+            dt1ds2 = a1j * (t1mi - t1j * MathSpecial::square(t1mi));
-            a2i = 0.0;
+            dt2ds1 = a2i * (t2mj - t2i * MathSpecial::square(t2mj));
-            a2j = 0.0;
+            dt2ds2 = a2j * (t2mi - t2j * MathSpecial::square(t2mi));
-            a3i = 0.0;
+            dt3ds1 = a3i * (t3mj - t3i * MathSpecial::square(t3mj));
-            a3j = 0.0;
+            dt3ds2 = a3j * (t3mi - t3j * MathSpecial::square(t3mi));
-            if (!iszero(tsq_ave[i][0]))
-              a1i = rhoa0j / tsq_ave[i][0];
-            if (!iszero(tsq_ave[j][0]))
-              a1j = rhoa0i / tsq_ave[j][0];
-            if (!iszero(tsq_ave[i][1]))
-              a2i = rhoa0j / tsq_ave[i][1];
-            if (!iszero(tsq_ave[j][1]))
-              a2j = rhoa0i / tsq_ave[j][1];
-            if (!iszero(tsq_ave[i][2]))
-              a3i = rhoa0j / tsq_ave[i][2];
-            if (!iszero(tsq_ave[j][2]))
-              a3j = rhoa0i / tsq_ave[j][2];
-
-            dt1ds1 = a1i * (t1mj - t1i * pow(t1mj, 2));
-            dt1ds2 = a1j * (t1mi - t1j * pow(t1mi, 2));
-            dt2ds1 = a2i * (t2mj - t2i * pow(t2mj, 2));
-            dt2ds2 = a2j * (t2mi - t2j * pow(t2mi, 2));
-            dt3ds1 = a3i * (t3mj - t3i * pow(t3mj, 2));
-            dt3ds2 = a3j * (t3mi - t3j * pow(t3mi, 2));
 
           } else if (this->ialloy == 2) {
 

src/USER-MEAMC/meam_funcs.cpp

@@ -162,11 +162,11 @@ MEAM::erose(const double r, const double re, const double alpha, const double Ec
       a3 = repuls;
 
     if (form == 1)
-      result = -Ec * (1 + astar + (-attrac + repuls / r) * pow(astar, 3)) * MathSpecial::fm_exp(-astar);
+      result = -Ec * (1 + astar + (-attrac + repuls / r) * MathSpecial::cube(astar)) * MathSpecial::fm_exp(-astar);
     else if (form == 2)
-      result = -Ec * (1 + astar + a3 * pow(astar, 3)) * MathSpecial::fm_exp(-astar);
+      result = -Ec * (1 + astar + a3 * MathSpecial::cube(astar)) * MathSpecial::fm_exp(-astar);
     else
-      result = -Ec * (1 + astar + a3 * pow(astar, 3) / (r / re)) * MathSpecial::fm_exp(-astar);
+      result = -Ec * (1 + astar + a3 * MathSpecial::cube(astar) / (r / re)) * MathSpecial::fm_exp(-astar);
   }
   return result;
 }

src/USER-MEAMC/meam_setup_done.cpp

@@ -375,16 +375,20 @@ MEAM::phi_meam(double r, int a, int b)
   if (this->lattce_meam[a][b] == C11) {
     latta = this->lattce_meam[a][a];
     if (latta == DIA) {
-      rhobar1 = pow(((Z12 / 2) * (rho02 + rho01)), 2) + t11av * pow((rho12 - rho11), 2) +
+      rhobar1 = MathSpecial::square((Z12 / 2) * (rho02 + rho01))
-                t21av / 6.0 * pow(rho22 + rho21, 2) + 121.0 / 40.0 * t31av * pow((rho32 - rho31), 2);
+                + t11av * MathSpecial::square(rho12 - rho11)
+                + t21av / 6.0 * MathSpecial::square(rho22 + rho21)
+                + 121.0 / 40.0 * t31av * MathSpecial::square(rho32 - rho31);
       rhobar1 = sqrt(rhobar1);
-      rhobar2 = pow(Z12 * rho01, 2) + 2.0 / 3.0 * t21av * pow(rho21, 2);
+      rhobar2 = MathSpecial::square(Z12 * rho01) + 2.0 / 3.0 * t21av * MathSpecial::square(rho21);
       rhobar2 = sqrt(rhobar2);
     } else {
-      rhobar2 = pow(((Z12 / 2) * (rho01 + rho02)), 2) + t12av * pow((rho11 - rho12), 2) +
+      rhobar2 = MathSpecial::square((Z12 / 2) * (rho01 + rho02))
-                t22av / 6.0 * pow(rho21 + rho22, 2) + 121.0 / 40.0 * t32av * pow((rho31 - rho32), 2);
+                + t12av * MathSpecial::square(rho11 - rho12)
+                + t22av / 6.0 * MathSpecial::square(rho21 + rho22)
+                + 121.0 / 40.0 * t32av * MathSpecial::square(rho31 - rho32);
       rhobar2 = sqrt(rhobar2);
-      rhobar1 = pow(Z12 * rho02, 2) + 2.0 / 3.0 * t22av * pow(rho22, 2);
+      rhobar1 = MathSpecial::square(Z12 * rho02) + 2.0 / 3.0 * t22av * MathSpecial::square(rho22);
       rhobar1 = sqrt(rhobar1);
     }
   } else {
@@ -560,31 +564,29 @@ MEAM::get_tavref(double* t11av, double* t21av, double* t31av, double* t12av, dou
     *t12av = t12;
     *t22av = t22;
     *t32av = t32;
+  } else if (latt == FCC || latt == BCC || latt == DIA || latt == HCP || latt == B1 || latt == DIM || latt == B2) {
+    //     all neighbors are of the opposite type
+    *t11av = t12;
+    *t21av = t22;
+    *t31av = t32;
+    *t12av = t11;
+    *t22av = t21;
+    *t32av = t31;
   } else {
-    if (latt == FCC || latt == BCC || latt == DIA || latt == HCP || latt == B1 || latt == DIM || latt == B2) {
+    a1 = r / this->re_meam[a][a] - 1.0;
-      //     all neighbors are of the opposite type
+    a2 = r / this->re_meam[b][b] - 1.0;
-      *t11av = t12;
+    rhoa01 = this->rho0_meam[a] * MathSpecial::fm_exp(-this->beta0_meam[a] * a1);
-      *t21av = t22;
+    rhoa02 = this->rho0_meam[b] * MathSpecial::fm_exp(-this->beta0_meam[b] * a2);
-      *t31av = t32;
+    if (latt == L12) {
+      rho01 = 8 * rhoa01 + 4 * rhoa02;
+      *t11av = (8 * t11 * rhoa01 + 4 * t12 * rhoa02) / rho01;
       *t12av = t11;
+      *t21av = (8 * t21 * rhoa01 + 4 * t22 * rhoa02) / rho01;
       *t22av = t21;
+      *t31av = (8 * t31 * rhoa01 + 4 * t32 * rhoa02) / rho01;
       *t32av = t31;
     } else {
-      a1 = r / this->re_meam[a][a] - 1.0;
+      //      call error('Lattice not defined in get_tavref.')
-      a2 = r / this->re_meam[b][b] - 1.0;
-      rhoa01 = this->rho0_meam[a] * MathSpecial::fm_exp(-this->beta0_meam[a] * a1);
-      rhoa02 = this->rho0_meam[b] * MathSpecial::fm_exp(-this->beta0_meam[b] * a2);
-      if (latt == L12) {
-        rho01 = 8 * rhoa01 + 4 * rhoa02;
-        *t11av = (8 * t11 * rhoa01 + 4 * t12 * rhoa02) / rho01;
-        *t12av = t11;
-        *t21av = (8 * t21 * rhoa01 + 4 * t22 * rhoa02) / rho01;
-        *t22av = t21;
-        *t31av = (8 * t31 * rhoa01 + 4 * t32 * rhoa02) / rho01;
-        *t32av = t31;
-      } else {
-        //      call error('Lattice not defined in get_tavref.')
-      }
     }
   }
 }
@@ -677,8 +679,8 @@ MEAM::get_densref(double r, int a, int b, double* rho01, double* rho11, double*
     *rho01 = 8 * rhoa01 + 4 * rhoa02;
     *rho02 = 12 * rhoa01;
     if (this->ialloy == 1) {
-      *rho21 = 8. / 3. * pow(rhoa21 * this->t2_meam[a] - rhoa22 * this->t2_meam[b], 2);
+      *rho21 = 8. / 3. * MathSpecial::square(rhoa21 * this->t2_meam[a] - rhoa22 * this->t2_meam[b]);
-      denom = 8 * rhoa01 * pow(this->t2_meam[a], 2) + 4 * rhoa02 * pow(this->t2_meam[b], 2);
+      denom = 8 * rhoa01 * MathSpecial::square(this->t2_meam[a]) + 4 * rhoa02 * MathSpecial::square(this->t2_meam[b]);
       if (denom > 0.)
         *rho21 = *rho21 / denom * *rho01;
     } else
@@ -768,25 +770,3 @@ MEAM::interpolate_meam(int ind)
     this->phirar6[ind][j] = 3.0 * this->phirar3[ind][j] / drar;
   }
 }
-
-//---------------------------------------------------------------------
-// Compute Rose energy function, I.16
-//
-double
-MEAM::compute_phi(double rij, int elti, int eltj)
-{
-  double pp;
-  int ind, kk;
-
-  ind = this->eltind[elti][eltj];
-  pp = rij * this->rdrar;
-  kk = (int)pp;
-  kk = std::min(kk, this->nrar - 2);
-  pp = pp - kk;
-  pp = std::min(pp, 1.0);
-  double result =
-    ((this->phirar3[ind][kk] * pp + this->phirar2[ind][kk]) * pp + this->phirar1[ind][kk]) * pp +
-    this->phirar[ind][kk];
-
-  return result;
-}