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qp2/src/bitmask/example.irp.f

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2019-01-25 11:39:31 +01:00
subroutine example_bitmask
use bitmasks ! you need to include the bitmasks_module.f90 features
implicit none
BEGIN_DOC
! subroutine that illustrates the main features available in bitmask
END_DOC
integer :: i,j
print*,''
print*,'**************'
print*,'**************'
print*,'MO class: to set the various type of MO class, see the following exectuable'
print*,'qp_set_mo_class'
print*,'**************'
print*,'number of core orbitals = ',n_core_orb
print*,'list of the core orbitals '
do i = 1, n_core_orb
write(*,'(2(I3,X))')i,list_core(i)
enddo
print*,'number of inact orbitals = ',n_inact_orb
print*,'list of the inact orbitals '
do i = 1, n_inact_orb
write(*,'(2(I3,X))')i,list_inact(i)
enddo
print*,'number of act orbitals = ',n_act_orb
print*,'list of the act orbitals '
do i = 1, n_act_orb
write(*,'(2(I3,X))')i,list_act(i)
enddo
print*,'number of virt orbitals = ',n_virt_orb
print*,'list of the virt orbitals '
do i = 1, n_virt_orb
write(*,'(2(I3,X))')i,list_virt(i)
enddo
print*,''
print*,'**************'
print*,'**************'
print*,'manipulating bitstrings (usefull for determinant representation)'
print*,'**************'
integer(bit_kind), allocatable :: key(:)
print*,'Size of the integers used to represent all the orbitals '
print*,'bit_kind = ',bit_kind
print*,'Number of bits in the integers ',bit_kind_size
print*,'Number of integers to represent all the orbitals on integer'
print*,'N_int = ',N_int
allocate(key(N_int))
print*,'**** '
print*,' initialize a bistring to zero '
do i = 1, N_int
key(i) = 0_bit_kind
enddo
print*,'print a human readable representation of the bitstring'
call bitstring_to_str( output, key, N_int )
print *, trim(output)
integer :: i_orb
character*(2048) :: output
do i_orb = 1, min(4,mo_num) ! you set the first four bits to 1 in key
call set_bit_to_integer(i_orb,key,N_int)
enddo
print*,'print a human readable representation of the bitstring'
call bitstring_to_str( output, key, N_int )
print *, trim(output)
print*,''
integer :: n_elements
integer, allocatable :: list_occ(:)
allocate(list_occ(N_int*bit_kind_size))
call bitstring_to_list( key, list_occ, n_elements, N_int)
print*,'number of bits set to 1 = ',n_elements
print*,'list of bits set to 1 '
do i = 1, n_elements
write(*,'(2(I3,X))')i,list_occ(i)
enddo
call clear_bit_to_integer(2,key,N_int) ! you set to 0 the second bit
print*,'print a human readable representation of the bitstring'
call bitstring_to_str( output, key, N_int )
print *, trim(output)
end