ergo
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Trace correcting purification. More...
#include <TC2.h>
Classes | |
class | Fun |
Help class for bisection root finding calls. More... | |
Public Member Functions | |
TC2 (Tmatrix &F, Tmatrix &DM, const int size, const int noc, const Treal trunc=0, const int maxmm=100) | |
Constructor Initializes everything. | |
Treal | fermi_level (Treal tol=1e-15) const |
Returns the Fermi level. | |
Treal | homo (Treal tol=1e-15) const |
Returns upper bound of the HOMO eigenvalue. | |
Treal | lumo (Treal tol=1e-15) const |
Returns lower bound of the LUMO eigenvalue. | |
int | n_multiplies () const |
Returns the number of used matrix matrix multiplications. | |
void | print_data (int const start, int const stop) const |
virtual | ~TC2 () |
Destructor. | |
Protected Member Functions | |
void | purify () |
Runs purification. | |
Protected Attributes | |
Tmatrix & | X |
Fock / Kohn-Sham matrix at initialization. | |
Tmatrix & | D |
Density matrix after purification. | |
const int | n |
System size. | |
const int | nocc |
Number of occupied orbitals. | |
const Treal | frob_trunc |
Threshold for the truncation. | |
const int | maxmul |
Number of tolerated matrix multiplications. | |
Treal | lmin |
Lower bound for eigenvalue spectrum. | |
Treal | lmax |
Upper bound for eigenvalue spectrum. | |
int | nmul |
Number of used matrix multiplications. | |
int | nmul_firstpart |
Number of used matrix multiplications in the first part of the purification. | |
Treal * | idemerror |
Upper bound of euclidean norm ||D-D^2||_2 before each step. | |
Treal * | tracediff |
The difference between the trace of the matrix and the number of occupied orbitals before each step. | |
int * | polys |
Choices of polynomials 0 for x^2 and 1 for 2x-x^2 Length: nmul. |
Trace correcting purification.
This template instantiates the trace correcting purification algorithm developed by Niklasson [Phys. Rev. B 66, 155115 (2002)] with modifications by Rubensson and Rudberg [unpublished]. The template can be used with any matrix class Tmatrix that has the following member functions:
The matrix class should also support the following syntax:
where A and B are of type Tmatrix and alpha and beta are of type Treal.
mat::TC2::TC2 | ( | Tmatrix & | F, |
Tmatrix & | DM, | ||
const int | size, | ||
const int | noc, | ||
const Treal | trunc = 0 , |
||
const int | maxmm = 100 |
||
) |
Constructor Initializes everything.
Constructor.
< Run purification
F | Fock/Kohn-Sham matrix (input/workspace) |
DM | Density matrix (output) |
size | System size (Number of basis functions) |
noc | Number of occupied orbitals. |
trunc | Threshold for truncation in Frobenius norm. |
maxmm | Maximum aloud number of mm-multiplications. |
References frob_trunc, nocc, maxmul, X, lmin, lmax, D, idemerror, tracediff, polys, and purify().
virtual mat::TC2::~TC2 | ( | ) | [inline, virtual] |
Treal mat::TC2::fermi_level | ( | Treal | tol = 1e-15 | ) | const |
Returns the Fermi level.
Run after call to purify().
tol | Fault-tolerance for result. |
References mat::bisection().
Treal mat::TC2::homo | ( | Treal | tol = 1e-15 | ) | const |
Returns upper bound of the HOMO eigenvalue.
Run after call to purify().
tol | Fault-tolerance for result. |
References template_blas_sqrt(), and mat::bisection().
Treal mat::TC2::lumo | ( | Treal | tol = 1e-15 | ) | const |
Returns lower bound of the LUMO eigenvalue.
Run after call to purify().
tol | Fault-tolerance for result. |
References template_blas_sqrt(), and mat::bisection().
int mat::TC2::n_multiplies | ( | ) | const [inline] |
Returns the number of used matrix matrix multiplications.
References nmul.
void mat::TC2::print_data | ( | int const | start, |
int const | stop | ||
) | const |
void mat::TC2::purify | ( | ) | [protected] |
Tmatrix& mat::TC2::D [protected] |
Density matrix after purification.
Referenced by TC2().
const Treal mat::TC2::frob_trunc [protected] |
Threshold for the truncation.
Referenced by TC2().
Treal* mat::TC2::idemerror [protected] |
Upper bound of euclidean norm ||D-D^2||_2 before each step.
This means: idemerror[i] = norm(D[i]-D[i]^2) where D[0] is the initial matrix and D[i] is the matrix after i steps in the purification. This value is calculated after the step since D[i]^2 or 2D[i] - D[i]^2 is needed. Length: nmul
Treal mat::TC2::lmax [protected] |
Upper bound for eigenvalue spectrum.
Referenced by TC2().
Treal mat::TC2::lmin [protected] |
Lower bound for eigenvalue spectrum.
Referenced by TC2().
const int mat::TC2::maxmul [protected] |
Number of tolerated matrix multiplications.
Referenced by TC2().
const int mat::TC2::n [protected] |
System size.
int mat::TC2::nmul [protected] |
Number of used matrix multiplications.
Referenced by n_multiplies().
int mat::TC2::nmul_firstpart [protected] |
Number of used matrix multiplications in the first part of the purification.
const int mat::TC2::nocc [protected] |
Number of occupied orbitals.
Referenced by TC2().
int* mat::TC2::polys [protected] |
Treal* mat::TC2::tracediff [protected] |
Tmatrix& mat::TC2::X [protected] |