NOTE: DFCOEF file was replaced by CHECKPOINT.h5 in DIRAC22, and the information below is only relevant for older versions of DIRAC.

DFCOEF

The binary DFCOEF file serves for storing molecular orbitals and related information.

In the Fortran language it can be written like

CHARACTER TEXT*74
DIMENSION CMO(NCMOTQ),EIG(NORBT),IBEIG(NORBT),IDIM(3,2)
DOUBLE PRECISION TOTERG

DO I = 1,NFSYM
  IDIM(1,I) = NPSH(I)
  IDIM(2,I) = NESH(I)
  IDIM(3,I) = NFBAS(I,0)
ENDDO
WRITE(IUNIT) TEXT,NFSYM,((IDIM(I,J),I = 1,3),J=1,NFSYM),TOTERG

Let i be the integer size (4 or 8) and d the double precision size (8). Size of the stored data, Size, given in first section above, is 74+i*(1+3*NFSYM)+d.

i NFSYM Size
4 1     74+4*4+8 = 98
4 2     74+4*7+8 = 110
8 1     74+8*4+8 = 114
8 2              = 138

After calculating the Size we can store remaining data:

• molecular orbitals coefficients, CMO

• SCF eigenvalues, EIG

• specification of the irreducible representation per orbital, IBEIG

WRITE(IUNIT) CMO   Size d*NCMOTQ
WRITE(IUNIT) EIG   Size d*NORBT
WRITE(IUNIT) IBEIG Size i*NORBT