## Documentation for module ao_util

All kind of helpfull little routines

source: ao_util.F

#### public Subroutines/Functions:

exp_radius (l, alpha, threshold, prefactor, epsin)
The radius of a primitive Gaussian function for a given threshold is calculated. g(r) = prefactor*r**l*exp(-alpha*r**2) - threshold = 0
computes the radius of the Gaussian outside of which it is smaller than eps
gaussint_sph (alpha, l)
...
The exponent of a primitive Gaussian function for a given radius and threshold is calculated.
trace_r_axb (a, lda, b, ldb, m, n)
...

#### FUNCTIONexp_radius(l, alpha, threshold, prefactor, epsin)^

The radius of a primitive Gaussian function for a given threshold is calculated. g(r) = prefactor*r**l*exp(-alpha*r**2) - threshold = 0

 Return Value :: REAL(dp)
##### Arguments:
 INTEGER, INTENT(in) :: l Angular momentum quantum number l. REAL(dp), INTENT(in) :: alpha Exponent of the primitive Gaussian function. REAL(dp), INTENT(in) :: threshold Threshold for radius. REAL(dp), INTENT(in) :: prefactor Prefactor of the Gaussian function (e.g. a contraction coefficient). REAL(dp), INTENT(in), OPTIONAL :: epsin Convergence criterion

#### FUNCTIONexp_radius_very_extended(la_min, la_max, lb_min, lb_max, pab, o1, o2, ra, rb, rp, zetp, eps, prefactor, cutoff, epsin)^

computes the radius of the Gaussian outside of which it is smaller than eps

 Return Value :: REAL(dp)
##### Arguments:
 INTEGER, INTENT(in) :: la_min ... INTEGER, INTENT(in) :: la_max ... INTEGER, INTENT(in) :: lb_min ... INTEGER, INTENT(in) :: lb_max ... REAL(dp), OPTIONAL, POINTER :: pab(:,:) ... INTEGER, OPTIONAL :: o1 ... INTEGER, OPTIONAL :: o2 ... REAL(dp), INTENT(in) :: ra(3) ... REAL(dp), INTENT(in) :: rb(3) ... REAL(dp), INTENT(in) :: rp(3) ... REAL(dp), INTENT(in) :: zetp ... REAL(dp), INTENT(in) :: eps ... REAL(dp), INTENT(in) :: prefactor ... REAL(dp), INTENT(in) :: cutoff ... REAL(dp), OPTIONAL :: epsin ...

#### FUNCTIONgaussint_sph(alpha, l)^

...

 Return Value :: REAL(dp)
##### Arguments:
 REAL(dp), INTENT(in) :: alpha ... INTEGER, INTENT(in) :: l ...

The exponent of a primitive Gaussian function for a given radius and threshold is calculated.

 Return Value :: REAL(dp)
##### Arguments:
 INTEGER, INTENT(in) :: l ... REAL(dp), INTENT(in) :: radius ... REAL(dp), INTENT(in) :: threshold ... REAL(dp), INTENT(in) :: prefactor ...

#### PURE FUNCTIONtrace_r_axb(a, lda, b, ldb, m, n)^

...

 Return Value :: REAL(dp)
##### Arguments:
 REAL(dp), INTENT(in) :: a(lda,*) ... INTEGER, INTENT(in) :: lda ... REAL(dp), INTENT(in) :: b(ldb,*) ... INTEGER, INTENT(in) :: ldb ... INTEGER, INTENT(in) :: m ... INTEGER, INTENT(in) :: n ...