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Dimensioning parameters

The following parameters are used (they are collected in file param.inc, except the IFFxx parameters, which are in lapw0.f):

IFFT1  parameters of 3-dimensional array for fast Fourier transform (FFT)
IFFT2 
IFFT3 
NATO   number of inequivalent atoms
NCOM   number of LM components in charge density and potential representation; it must satisfy the following condition: NCOM+3 .gt.
$\{$[number of L,M with M=0] + [2 * number of L,M with M>0] $\}$
NDIF   total number of atoms per unit cell
NRAD   number of radial mesh points
NSTD   defines the angular grid points used in fit for xc-potential inside spheres
LMAX1D   defines the angular grid points used in fit for xc-potential inside spheres
LMAX2   highest L in in LM expansion of charge and potential
NSYM   order of point group
NWAV   number of stars in Fourier series of density and potential

In order to bring about a sort of dynamical dimensioning, arrays for the FFT are defined in the main program allocating storage space, which is passed to subroutines where the arrays are used with the actual parameters (computed at run-time in IFFLIM); the latter are labeled IFF1, IFF2, IFF3 (omitting T). Therefore the following global conditions must be satisfied:

the IFFi must be .ge.[ Kmax(i) component +1]*2, where Kmax(i)represents the largest h,k,l components in the Fourier series they must be multiples of 2, 3, or 5;

IFFT1*IFFT2*IFFT3 .ge. IFF1*IFF2*IFF3
IFFT1+IFFT2+IFFT3 .ge. MAX(IFF1,IFF2,IFF3)


next up previous contents
Next: Input Up: LAPW0 (generates potential) Previous: Execution

2000-04-11