class rgpot::XcKernel¶

Overview¶

class XcKernel {
public:
    // typedefs
 
    typedef int(*)(std::int64_t npts, std::int64_t nbf, const double*chi, const double*dchi, const double*lapl_chi, const double*hess_chi, const double*const*scal, double*out) KernelFn;
 
    // construction
 
    XcKernel(std::string name);
 
    // methods
 
    const std::string& name() const;
    std::vector<std::string> scalNames() const;
    int nScal() const;
    int nFields() const;
    int contract(const XcGrid& grid, const std::map<std::string, const double*>& scal, double* out) const;
    int applyFxc(const XcGrid& grid, const std::map<std::string, const double*>& ground, const double* dm, double* vxc) const;
    int tdaSigma(const XcGrid& grid, const std::map<std::string, const double*>& ground, const XcMo& mo, const double* z, const double* vj, double* sigma) const;
    int rpaSigma(const XcGrid& grid, const std::map<std::string, const double*>& ground, const XcMo& mo, const double* xy, const double* vj, double* sigma) const;
    static std::vector<std::string> catalog();
    static XcFields fieldsFromDensity(const XcGrid& grid, const double* P);
    static void transitionDm(const XcMo& mo, const double* z, double occ, double* dm);
    static void rpaTransitionDm(const XcMo& mo, const double* x, const double* y, double occ, double* dm);
    static void projectOv(const XcMo& mo, const double* Vao, double* ov);
    static void tdaSigma(const XcMo& mo, const double* z, const double* v1, double* sigma);
    static void rpaSigma(const XcMo& mo, const double* xy, const double* v1, double* sigma);
};

Detailed Documentation¶

Construction¶

XcKernel(std::string name)

Resolve a first-slice catalog name, e.g. “xck_gga_r_o2”.

Methods¶

int contract(const XcGrid& grid, const std::map<std::string, const double*>& scal, double* out) const

Assemble scal in <name>_scal_names order and accumulate into out (nbf * nbf, +=). Returns the C ABI rc (0 on success).

int applyFxc(const XcGrid& grid, const std::map<std::string, const double*>& ground, const double* dm, double* vxc) const

XC fxc on one AO density via this kernel. Ground-state scal holds weights, Libxc arrays, and (GGA) grad_rho_a_*. Perturbed rho/grad names (rho_a_p1, grad_rho_a_p1_*) are built from dm. Accumulates into vxc (nao*nao, +=).

int tdaSigma(const XcGrid& grid, const std::map<std::string, const double*>& ground, const XcMo& mo, const double* z, const double* vj, double* sigma) const

TDA sigma with host Coulomb: v1 = vj + 0.5 * applyFxc(dm(z)). vj is the host J matrix on the transition DM (nao*nao).

int rpaSigma(const XcGrid& grid, const std::map<std::string, const double*>& ground, const XcMo& mo, const double* xy, const double* vj, double* sigma) const

RPA sigma with host Coulomb on dm(X,Y). xy/out are 2*nocc*nvir.

static std::vector<std::string> catalog()

Known first-slice contraction names (o1 Fock + o2 fxc). Empty if the translation unit was compiled without -Dwith_xckernel.

static XcFields fieldsFromDensity(const XcGrid& grid, const double* P)

Convenience: build rho / sigma / tau / lapl / grad_rho from an AO density (symmetric or transition). Host still evaluates Libxc.

static void transitionDm(const XcMo& mo, const double* z, double occ, double* dm)

dm = einsum(‘qo,ov,pv->pq’, Co*occ, z, Cv). Matches lib.einsum path (‘qo,xov->vxq’ then ‘vxq,pv->xpq’) used by TDA.gen_vind.

static void rpaTransitionDm(const XcMo& mo, const double* x, const double* y, double occ, double* dm)

dm = einsum X plus einsum(‘po,ov,qv->pq’, Co*occ, y, Cv) (‘po,xov->vxp’ then ‘vxp,qv->xpq’).

static void projectOv(const XcMo& mo, const double* Vao, double* ov)

ov = einsum(‘pv,pq,qo->ov’, Cv, V, Co) == Co^T @ (V^T @ Cv). Matches lib.einsum path (‘pv,xpq->vxq’ then ‘vxq,qo->xov’).

static void tdaSigma(const XcMo& mo, const double* z, const double* v1, double* sigma)

(A z)_ia = e_ia z_ia + (Co^T @ v1^T @ Cv)_ia. v1 is AO (nao*nao).

static void rpaSigma(const XcMo& mo, const double* xy, const double* v1, double* sigma)

[[A,B],[-B,-A]](X,Y). xy and out are 2*nocc*nvir (X then Y).