Added simple cubic

Added simple cubic as the reference structure

doc/src/pair_meam.rst

@@ -238,6 +238,7 @@ The recognized keywords for the parameter file are as follows:
                    lin = linear structure (180 degree angle)
                    zig = zigzag structure with a uniform angle
                    tri = H2O-like structure that has an angle
+				   sc = simple cubic
    nn2(I,J)    = turn on second-nearest neighbor MEAM formulation for
                  I-J pair (see for example :ref:`(Lee) <Lee>`).
                    0 = second-nearest neighbor formulation off

src/MEAM/meam.h

@@ -22,7 +22,7 @@
 namespace LAMMPS_NS {
 class Memory;
 
-typedef enum { FCC, BCC, HCP, DIM, DIA, DIA3, B1, C11, L12, B2, CH4, LIN, ZIG, TRI } lattice_t;
+typedef enum { FCC, BCC, HCP, DIM, DIA, DIA3, B1, C11, L12, B2, CH4, LIN, ZIG, TRI, SC } lattice_t;
 
 class MEAM {
  public:
@@ -263,6 +263,7 @@ class MEAM {
     else if (str == "lin") lat = LIN;
     else if (str == "zig") lat = ZIG;
     else if (str == "tri") lat = TRI;
+    else if (str == "sc") lat = SC;
     else {
       if (single)
         return false;

src/MEAM/meam_funcs.cpp

@@ -208,6 +208,7 @@ MEAM::get_shpfcn(const lattice_t latt, const double sthe, const double cthe, dou
     case BCC:
     case B1:
     case B2:
+    case SC:
       s[0] = 0.0;
       s[1] = 0.0;
       s[2] = 0.0;
@@ -267,6 +268,7 @@ MEAM::get_Zij(const lattice_t latt)
     case DIM:
       return 1;
     case B1:
+	case SC:
       return 6;
     case C11:
       return 10;
@@ -320,6 +322,7 @@ MEAM::get_Zij2(const lattice_t latt, const double cmin, const double cmax,
     break;
 
   case B1:
+  case SC:
     Zij2 = 12;
     a = sqrt(2.0);
     numscr = 2;

src/MEAM/meam_setup_done.cpp

@@ -615,6 +615,7 @@ void MEAM::get_tavref(double* t11av, double* t21av, double* t31av, double* t12av
     case LIN:
     case ZIG:
     case TRI:
+    case SC:
       //     all neighbors are of the opposite type
       *t11av = t12;
       *t21av = t22;
@@ -698,6 +699,7 @@ void MEAM::get_densref(double r, int a, int b, double* rho01, double* rho11, dou
       *rho02 = 8.0 * rhoa01;
       break;
     case B1:
+    case SC:
       *rho01 = 6.0 * rhoa02;
       *rho02 = 6.0 * rhoa01;
       break;

src/MEAM/meam_setup_global.cpp

@@ -76,6 +76,7 @@ MEAM::meam_setup_global(int nelt, lattice_t* lat, int* ielement, double* /*atwt*
       case LIN:
       case ZIG:
       case TRI:
+      case SC:
         this->re_meam[i][i] = tmplat[i];
         break;
       case DIA: