deal with the Fermi distribution, compute it, fix mu, get derivs More...

Functions/Subroutines
subroutine, public	fermi (f, n, kts, e, mu, t, maxocc, estate, festate)
	returns occupations according to Fermi-Dirac statistics for a given set of energies and fermi level. Note that singly occupied orbitals are assumed

subroutine, public	fermifixed (f, mu, kts, e, n, t, maxocc, estate, festate)
	returns occupations according to Fermi-Dirac statistics for a given set of energies and number of electrons. Note that singly occupied orbitals are assumed. could fail if the fermi level lies out of the range of eigenvalues (to be fixed)

subroutine, public	fermikp (f, mu, kts, e, nel, wk, t, maxocc)
	Bisection search to find mu for a given nel (kpoint case)

subroutine, public	fermikp2 (f, mu, kts, e, nel, wk, t)
	Bisection search to find mu for a given nel (kpoint case)

subroutine, public	fermifixedderiv (dfde, f, mu, kts, e, n, t, maxocc, l, estate, festate)
	returns f and dfde for a given set of energies and number of electrons it is a numerical derivative, trying to use a reasonable step length it ought to yield an accuracy of approximately EPSILON()^(2/3) (~10^-11) l ~ 10*T yields best accuracy Note that singly occupied orbitals are assumed. To be fixed: this could be parallellized for better efficiency

Detailed Description

deal with the Fermi distribution, compute it, fix mu, get derivs

Author: Joost VandeVondele

Date: 09.2008

Function/Subroutine Documentation

◆ fermi()

subroutine, public fermi_utils::fermi	(	real(kind=dp), dimension(:), intent(out)	f,
		real(kind=dp), intent(out)	n,
		real(kind=dp), intent(out)	kts,
		real(kind=dp), dimension(:), intent(in)	e,
		real(kind=dp), intent(in)	mu,
		real(kind=dp), intent(in)	t,
		real(kind=dp), intent(in)	maxocc,
		integer, intent(in), optional	estate,
		real(kind=dp), intent(in), optional	festate
	)

returns occupations according to Fermi-Dirac statistics for a given set of energies and fermi level. Note that singly occupied orbitals are assumed

Parameters

f	occupations
N	total number of electrons (output)
kTS	...
e	eigenvalues
mu	Fermi level (input)
T	electronic temperature
maxocc	maximum occupation of an orbital
estate	excited state in core level spectroscopy
festate	occupation of the excited state in core level spectroscopy

Date: 09.2008

History

Made estate and festate optional (LT, 2014/02/26)

Author: Joost VandeVondele

Definition at line 47 of file fermi_utils.F.

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◆ fermifixed()

subroutine, public fermi_utils::fermifixed	(	real(kind=dp), dimension(:), intent(out)	f,
		real(kind=dp), intent(out)	mu,
		real(kind=dp), intent(out)	kts,
		real(kind=dp), dimension(:), intent(in)	e,
		real(kind=dp), intent(in)	n,
		real(kind=dp), intent(in)	t,
		real(kind=dp), intent(in)	maxocc,
		integer, intent(in), optional	estate,
		real(kind=dp), intent(in), optional	festate
	)

returns occupations according to Fermi-Dirac statistics for a given set of energies and number of electrons. Note that singly occupied orbitals are assumed. could fail if the fermi level lies out of the range of eigenvalues (to be fixed)

Parameters

f	occupations
mu	Fermi level (output)
kTS	...
e	eigenvalues
N	total number of electrons (input)
T	electronic temperature
maxocc	maximum occupation of an orbital
estate	excited state in core level spectroscopy
festate	occupation of the excited state in core level spectroscopy

Date: 09.2008

History

Made estate and festate optional (LT, 2014/02/26)

Author: Joost VandeVondele

Definition at line 201 of file fermi_utils.F.

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◆ fermikp()

subroutine, public fermi_utils::fermikp	(	real(kind=dp), dimension(:, :), intent(out)	f,
		real(kind=dp), intent(out)	mu,
		real(kind=dp), intent(out)	kts,
		real(kind=dp), dimension(:, :), intent(in)	e,
		real(kind=dp), intent(in)	nel,
		real(kind=dp), dimension(:), intent(in)	wk,
		real(kind=dp), intent(in)	t,
		real(kind=dp), intent(in)	maxocc
	)

Bisection search to find mu for a given nel (kpoint case)

Parameters

f	Occupation numbers
mu	chemical potential
kTS	Entropic energy contribution
e	orbital (band) energies
nel	Number of electrons (total)
wk	kpoint weights
t	Temperature
maxocc	Maximum occupation

Definition at line 282 of file fermi_utils.F.

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◆ fermikp2()

subroutine, public fermi_utils::fermikp2	(	real(kind=dp), dimension(:, :, :), intent(out)	f,
		real(kind=dp), intent(out)	mu,
		real(kind=dp), intent(out)	kts,
		real(kind=dp), dimension(:, :, :), intent(in)	e,
		real(kind=dp), intent(in)	nel,
		real(kind=dp), dimension(:), intent(in)	wk,
		real(kind=dp), intent(in)	t
	)

Bisection search to find mu for a given nel (kpoint case)

Parameters

f	Occupation numbers
mu	chemical potential
kTS	Entropic energy contribution
e	orbital (band) energies
nel	Number of electrons (total)
wk	kpoint weights
t	Temperature

Definition at line 335 of file fermi_utils.F.

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◆ fermifixedderiv()

subroutine, public fermi_utils::fermifixedderiv	(	real(kind=dp), dimension(:, :), intent(out)	dfde,
		real(kind=dp), dimension(:), intent(out)	f,
		real(kind=dp), intent(out)	mu,
		real(kind=dp), intent(out)	kts,
		real(kind=dp), dimension(:), intent(in)	e,
		real(kind=dp), intent(in)	n,
		real(kind=dp), intent(in)	t,
		real(kind=dp), intent(in)	maxocc,
		real(kind=dp), intent(in)	l,
		integer, intent(in), optional	estate,
		real(kind=dp), intent(in), optional	festate
	)

returns f and dfde for a given set of energies and number of electrons it is a numerical derivative, trying to use a reasonable step length it ought to yield an accuracy of approximately EPSILON()^(2/3) (~10^-11) l ~ 10*T yields best accuracy Note that singly occupied orbitals are assumed. To be fixed: this could be parallellized for better efficiency

Parameters

dfde	derivatives of the occupation numbers with respect to the eigenvalues the ith column is the derivative of f wrt to e_i
f	occupations
mu	Fermi level (input)
kTS	...
e	eigenvalues
N	total number of electrons (output)
T	electronic temperature
maxocc	...
l	typical length scale (~ 10 * T)
estate	...
festate	...

Date: 09.2008

History

Made estate and festate optional (LT, 2014/02/26)
Changed order of input, so l is before the two optional variables (LT, 2014/02/26)

Author: Joost VandeVondele

Definition at line 412 of file fermi_utils.F.

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Functions/Subroutines

Detailed Description

Function/Subroutine Documentation

◆ fermi()

◆ fermifixed()

◆ fermikp()

◆ fermikp2()

◆ fermifixedderiv()