MOLPRO

56 MATRIX OPERATIONS 385
56.8 Transforming operators (TRAN)
TRAN,result, Op, C
calculates result = C(T)*Op*C. The strings result, C, and Op are the internal names of the
matrices. If a backquote (‘) is appended to C or Op the corresponding matrix is transposed
before the operation. Thus,
TRAN,result, Op, C‘
computes result = C*Op*C(T).
56.9 Transforming density matrices into the MO basis (DMO)
DMO,result, D, C
calculates result = C(T)*S*D*S*C. The strings result, C, and D are internal names.
56.10 Diagonalizing a matrix DIAG
DIAG,eigvec,eigval,matrix [,iprint]
Diagonalizes matrix. The eigenvectors and eigenvalues are stored internally with associated
names eigvec and eigval, respectively (arbitrary strings of up to 16 characters). The if iprint.gt.0,
the eigenvalues are printed. If iprint.gt.1, also the eigenvectors are printed.
56.11 Generating natural orbitals (NATORB)
NATORB,name,dens,thresh
computes natural orbitals for density matrix dens. Orbitals with occupation numbers greater or
equal to thresh (default 1.d-4) are printed.
56.12 Forming an outer product of two vectors (OPRD)
OPRD,result,matrix,orb1,orb2,factor
Takes the column vectors v1 and v2 from matrix and adds their outer product to result. v1 and v2
must be given in the form icol.isym, e.g., 3.2 means the third vector in symmetry 2. The result
is
result(a,b) = result(a,b) + f actor ∗ v1(a) ∗ v2(b)
If result has not been used before, it is zeroed before performing the operation.
56.13 Combining matrix columns (ADDVEC)
ADDVEC,result,orbr,source,orbs,factor
Takes the column vector orbs from source and adds it to columnn orbr of result. v1 and v2 must
be given in the form icol.isym, e.g., 3.2 means the third vector in symmetry 2.