Library subroutines

The code HFODD requires an external subroutine which diagonalizes complex hermitian matrices. Version (v1.75r) contains an interface to the LAPACK subroutine ZHPEV that can be downloaded (with dependencies) from
http://netlib2.cs.utk.edu/cgi-bin/netlibfiles.pl?filename=/lapack/complex16/zhpev.f
This subroutine and its dependencies are in the REAL*8 and COMPLEX*16 versions, and should be compiled without promoting real numbers to the double precision. On the other hand, the code HFODD itself does require compilation with an option promoting to double precision. Therefore, the code and the ZHPEV package should be compiled separately, and then should be linked together.

In order to activate the interface to the LAPACK ZHPEV subroutine, the following modifications of the code HFODD (v1.75r) have to be made:

1.

Change everywhere the value of parameter I_CRAY=1 into I_CRAY=0.

2.

Change everywhere the value of parameter IZHPEV=0 into IZHPEV=1.

3.

Change the name of the subroutine ZHPEV, provided with the code HFODD, to another name, or remove it from the file.

4.

If your compiler does not support undefined externals, or subroutines called with different parameters, remove calls to subroutines CGEMM, F02AXE, and the first call to ZHPEV.