********>Bugfix 26
Author: Ross Walker
Date: 12/13/2006

Programs: Sander

Description: When running QMMM calculations with an incorrect spin
             state sander can quit with a cryptic error message instead
             of the intended error message.

Fix:  apply the following patch to src/sander/qm2_load_params.f

------------------------------------------------------------------------------
*** qm2_load_params_and_allocate.f	2006-12-13 15:35:31.000000000 -0800
--- qm2_load_params_and_allocate.f	2006-12-13 16:56:58.000000000 -0800
***************
*** 138,145 ****
        !Protect DUMB users from STUPID errors
        if (nelectrons > 2*qm2_struct%norbs) then
          if (qmmm_mpi%master.and.qmmm_struct%qm_mm_first_call) then
!           write(6,'(''QMMM: ERROR-number of electrons: ,i5, is more'')') nelectrons
!           write(6,'(''QMMM: than 2xnorbs of: ,i5'')') qm2_struct%norbs
            write(6,'(''QMMM: Check qmcharge in qmmm namelist and rerun'')')                                            
            write(6,'(''QMMM: the calculation.'')')                                                                     
          end if                                                                                                    
--- 138,145 ----
        !Protect DUMB users from STUPID errors
        if (nelectrons > 2*qm2_struct%norbs) then
          if (qmmm_mpi%master.and.qmmm_struct%qm_mm_first_call) then
!           write(6,'(''QMMM: ERROR-number of electrons: '',i5,'' is more'')') nelectrons
!           write(6,'(''QMMM: than 2xnorbs of: '',i5)') qm2_struct%norbs
            write(6,'(''QMMM: Check qmcharge in qmmm namelist and rerun'')')                                            
            write(6,'(''QMMM: the calculation.'')')                                                                     
          end if                                                                                                    
***************
*** 150,156 ****
  !        Make sure we have an even number of electrons
           if((nelectrons/2)*2 /= nelectrons) THEN
             if (qmmm_mpi%master.and.qmmm_struct%qm_mm_first_call) then
!              write(6,'(''QMMM: System specified with odd number of electrons ''('',i5,''))') nelectrons
               write(6,'(''QMMM: but odd spin ('',i3,''). Correct error and re-run calculation.'')') qmmm_nml%spin
             end if
             stop
--- 150,156 ----
  !        Make sure we have an even number of electrons
           if((nelectrons/2)*2 /= nelectrons) THEN
             if (qmmm_mpi%master.and.qmmm_struct%qm_mm_first_call) then
!              write(6,'(''QMMM: System specified with odd number of electrons ('',i5,'')'')') nelectrons
               write(6,'(''QMMM: but odd spin ('',i3,''). Correct error and re-run calculation.'')') qmmm_nml%spin
             end if
             stop
***************
*** 159,166 ****
  !        Make sure we have an odd number of electrons.`
           if((nelectrons/2)*2 == nelectrons) then
             if (qmmm_mpi%master.and.qmmm_struct%qm_mm_first_call) then
!              write(6,'(''QMMM: System specified with odd number of electrons ('',i5,'')'')') nelectrons
!              write(6,'(''QMMM: but odd spin ('',i3,''). Correct error and re-run calculation.'')') qmmm_nml%spin
             end if
             stop
           end if
--- 159,166 ----
  !        Make sure we have an odd number of electrons.`
           if((nelectrons/2)*2 == nelectrons) then
             if (qmmm_mpi%master.and.qmmm_struct%qm_mm_first_call) then
!              write(6,'(''QMMM: System specified with an even number of electrons ('',i5,'')'')') nelectrons
!              write(6,'(''QMMM: but even spin ('',i3,''). Correct error and re-run calculation.'')') qmmm_nml%spin
             end if
             stop
           end if
------------------------------------------------------------------------------
Temporary workarounds: None