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Added support for PBEsol exchange-correlation functional #4

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Added support for PBEsol exchange-correlation functional #4

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9 changes: 4 additions & 5 deletions src/PBEFunctional.C
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Original file line number Diff line number Diff line change
Expand Up @@ -23,8 +23,11 @@
#include <vector>
using namespace std;

PBEFunctional::PBEFunctional(const vector<vector<double> > &rhoe,
PBEFunctional::PBEFunctional(const vector<vector<double> > &rhoe, bool sol,
double x_coeff, double c_coeff)
: sol(sol),
um(sol ? 10./81 : 0.2195149727645171),
bet(sol ? 0.046 : 0.06672455060314922)
{
x_coeff_ = x_coeff;
c_coeff_ = c_coeff;
Expand Down Expand Up @@ -171,15 +174,13 @@ void PBEFunctional::excpbe(double rho, double grad,
const double third = 1.0 / 3.0;
const double third4 = 4.0 / 3.0;
const double ax = -0.7385587663820224058; /* -0.75*pow(3.0/pi,third) */
const double um = 0.2195149727645171;
const double uk = 0.804;
const double ul = um / uk;
const double pi32third = 3.09366772628014; /* (3*pi^2 ) ^(1/3) */
const double alpha = 1.91915829267751; /* pow(9.0*pi/4.0, third)*/
const double seven_sixth = 7.0 / 6.0;
const double four_over_pi = 1.27323954473516;
const double gamma = 0.03109069086965489; /* gamma = (1-ln2)/pi^2 */
const double bet = 0.06672455060314922; /* see [a] (4) */
const double delt = bet / gamma;

double rtrs,fk,twoks,rs,t,h,
Expand Down Expand Up @@ -290,7 +291,6 @@ void PBEFunctional::excpbe_sp(double rho_up, double rho_dn,
const double third4 = 4.0 / 3.0;
const double sixthm = -1.0 / 6.0;
const double ax = -0.7385587663820224058; /* -0.75*pow(3.0/pi,third) */
const double um = 0.2195149727645171;
const double uk = 0.804;
const double ul = um / uk;
const double pi32third = 3.09366772628014; /* (3*pi^2 ) ^(1/3) */
Expand All @@ -300,7 +300,6 @@ void PBEFunctional::excpbe_sp(double rho_up, double rho_dn,
const double gam = 0.5198420997897463; /* gam = 2^(4/3) - 2 */
const double fzz = 8.0 / ( 9.0 * gam );
const double gamma = 0.03109069086965489; /* gamma = (1-ln2)/pi^2 */
const double bet = 0.06672455060314922; /* see [a] (4) */
const double delt = bet / gamma;
const double eta = 1.e-12; // small number to avoid blowup as |zeta|->1

Expand Down
8 changes: 5 additions & 3 deletions src/PBEFunctional.h
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Expand Up @@ -24,6 +24,8 @@

class PBEFunctional : public XCFunctional
{
const bool sol; //!< PBEsol, if true
const double um, bet; //!< only constants that change between PBE and PBEsol
double x_coeff_, c_coeff_;
std::vector<double> _exc, _exc_up, _exc_dn;
std::vector<double> _vxc1, _vxc1_up, _vxc1_dn,
Expand All @@ -46,12 +48,12 @@ class PBEFunctional : public XCFunctional
public:

// constructor with variable coefficients for exchange and correlation
// with default values 1.0
PBEFunctional(const std::vector<std::vector<double> > &rhoe,
// with default values 1.0, and sol = true/false switches between PBE and PBEsol
PBEFunctional(const std::vector<std::vector<double> > &rhoe, bool sol,
double x_coeff=1.0, double c_coeff=1.0);

bool isGGA() const { return true; };
std::string name() const { return "PBE"; };
std::string name() const { return (sol ? "PBEsol" : "PBE"); };
void setxc(void);
};
#endif
1 change: 1 addition & 0 deletions src/XCOperator.C
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Expand Up @@ -40,6 +40,7 @@ XCOperator::XCOperator(Sample& s, const ChargeDensity& cd) :cd_(cd)
if ( ( functional_name == "LDA" ) ||
( functional_name == "VWN" ) ||
( functional_name == "PBE" ) ||
( functional_name == "PBEsol" ) ||
( functional_name == "BLYP" ) )
{
// create only an xc potential
Expand Down
8 changes: 6 additions & 2 deletions src/XCPotential.C
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Expand Up @@ -48,7 +48,11 @@ XCPotential::XCPotential(const ChargeDensity& cd, const string functional_name,
}
else if ( functional_name == "PBE" )
{
xcf_ = new PBEFunctional(rhototal_r_);
xcf_ = new PBEFunctional(rhototal_r_, false);
}
else if ( functional_name == "PBEsol" )
{
xcf_ = new PBEFunctional(rhototal_r_, true);
}
else if ( functional_name == "BLYP" )
{
Expand All @@ -58,7 +62,7 @@ XCPotential::XCPotential(const ChargeDensity& cd, const string functional_name,
{
const double x_coeff = 1.0 - ctrl.alpha_PBE0;
const double c_coeff = 1.0;
xcf_ = new PBEFunctional(rhototal_r_,x_coeff,c_coeff);
xcf_ = new PBEFunctional(rhototal_r_,false,x_coeff,c_coeff);
}
else if ( functional_name == "HSE" )
{
Expand Down
3 changes: 2 additions & 1 deletion src/Xc.h
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Original file line number Diff line number Diff line change
Expand Up @@ -47,6 +47,7 @@ class Xc : public Var
if ( !( v == "LDA" ||
v == "VWN" ||
v == "PBE" ||
v == "PBEsol" ||
v == "BLYP" ||
v == "HF" ||
v == "PBE0" ||
Expand All @@ -56,7 +57,7 @@ class Xc : public Var
v == "BHandHLYP" ) )
{
if ( ui->onpe0() )
cout << " xc must be LDA, VWN, PBE, BLYP, "
cout << " xc must be LDA, VWN, PBE, PBEsol, BLYP, "
<< "HF, PBE0, HSE, RSH, B3LYP or BHandHLYP" << endl;
return 1;
}
Expand Down
2 changes: 1 addition & 1 deletion src/testXCFunctional.C
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Expand Up @@ -51,7 +51,7 @@ int main(int argc, char **argv)

XCFunctional *xcf_list[2];
xcf_list[0] = new LDAFunctional(rh);
xcf_list[1] = new PBEFunctional(rh);
xcf_list[1] = new PBEFunctional(rh, false);

for ( int ixcf = 0; ixcf < 2; ixcf++ )
{
Expand Down