Next: External module function estates
Up: Basic Module Functions
Previous: External module function Icalc_parameter_storage_matrix_init
Contents
Index
External module function du1calc - used by mcdisp,
singleion
The external single ion module has to provide the components nofcomponentsxnofcomponents
matrix
(see equation (77)) for every transition
which is to be taken into consideration
in the calculation. Note, in general
it is a quadratic matrix with the same
dimension as the vectors and Hxc.
Actually it is not necessary to compute the whole Matrix
, because
only the first eigenvector is needed in the computations.
Thus, in order to make calculations easier and provide a unique phase of the eigenvectors, the
external single ion module must return not the Matrix but the unnormalized
eigenvector , which is given by equation (79):
.
Note that in contrast to
the eigenvector
is not normalised (no !)
and thus the matrix
may be recovered from it.
The format to be used is:
extern "C" int du1calc(int & tn,double & T,Vector & Hxc,Vector & Hext,double * g_J,Vector & MODPAR,
char ** sipffilename,ComplexVector & u1,float & delta, ComplexMatrix & est)
The meaning of the symbols is as follows:
on input
|tn| transition-number
sign(tn) >0 standard, <0 routine should do some printout to stdout for user information
MODPAR Vector with Parameters read in single ion property file
sipffilename file name of the single ion parameter file
g_J Lande factor
T Temperature[K]
Hxc vector of exchange field [meV] (can be n-dimensional, for a set of n operators)
Hext external magnetic field [T]
est eigenstate matrix (initialized by estates)
it should/may also contain population numbers of the states
(imaginary part of row 0)
and eigenvalues (real part of row 0) with values set by the most recent call
for this ion (use of this matrix is optional)
u1(1) ninit + i pinit (from mcdisp options -ninit and -pinit)
delta upper boundary for transition energy (meV) to be considered
(from mcdisp option -maxE)
on output
int total number of transitions
delta transition energy [meV]
u1 vector u1=<-|Ialpha-<Ialpha>|+>sqrt((p- - p+))
note that as in Icalc the single ion momentum vector <-|I|+>
(n- dimensional with n>=1)
may be an arbitrary set of operators
The module function must perform the following tasks:
- check if the dimensions of vectors I,Hxc (taken by mcphas from the number of
interaction constant columns in mcphas.j)
and MODPAR (taken by mcphas from the number of params in the single ion property
file) agree with the module specifications. Note a module may be designed to
take different dimensions depending on the input files, however the dimensions
of vectors I and Hxc has to agree and must be within the range of dimensions which
can be treated by the module. If the check fails the module function should exit the
program with an appropriate error message
- the module function should do a numbering of all possible single ion transitions and return
the total number of transitions as an integer. Input file parameters params are supplied as a vector MODPAR and
Lande factor as g_J and can be used for this purpose. The numbering will depend on
the parameters ninit, pinit and maxE which are provided as input. These parameters
have to be considered. IMPORTANT: the numbering scheme of transitions has to
be the same for du1calc and all the corresponding d...1 functions for observables !
- it should calculate from meanfields at a given temperature the
transition energy of transition number tn. The result should be returned as delta
- for the transition number tn the vector u1 is to
be filled with
.
- If the energy of this transition
is zero, i.e. (diffuse scattering),
the expression (77) would be zero because vanishes.
In this case the single ion module should calculate instead of .
- if transition is from a level to itself, then a negative
value of
should be returned.
- if all quantities should be evaluated assuming that all Boltzmann probabilities
are zero except for the state number , for which the probability .
Next: External module function estates
Up: Basic Module Functions
Previous: External module function Icalc_parameter_storage_matrix_init
Contents
Index
martin rotter
2013-09-19