struct MOInfo {
  int nirreps;           /* no. of irreducible representations */
  int nmo;               /* no. of molecular orbitals */
  int nso;               /* no. of symmetry orbitals */
  int iopen;             /* 0=closed shell; >0=open shell */
  int phase;             /* Boolean for consistency of orbital phases */
  int aobasis;
  int *orbspi;           /* no. of MOs per irrep */
  int *orbsym;           /* orbital symmetry (Pitzer/SO) */
  int *clsdpi;           /* no. of closed-shells per irrep excl. frdocc */
  int *openpi;           /* no. of open-shells per irrep */
  int *uoccpi;           /* no. of unoccupied orbitals per irr. ex. fruocc */
  int *frdocc;           /* no. of frozen core orbitals per irrep */
  int *fruocc;           /* no. of frozen unoccupied orbitals per irrep */
  char **labels;         /* irrep labels */
  int *occpi;            /* no. of occupied orbs. (incl. open) per irrep */
  int *aoccpi;           /* no. of alpha occupied orbs. (incl. open) per irrep */
  int *boccpi;           /* no. of beta occupied orbs. (incl. open) per irrep */
  int *virtpi;           /* no. of virtual orbs. (incl. open) per irrep */
  int *avirtpi;          /* no. of alpha virtual orbs. (incl. open) per irrep */
  int *bvirtpi;          /* no. of beta virtual orbs. (incl. open) per irrep */
  int *occ_sym;          /* relative occupied index symmetry */
  int *aocc_sym;         /* relative alpha occupied index symmetry */
  int *bocc_sym;         /* relative beta occupied index symmetry */
  int *vir_sym;          /* relative virtual index symmetry */
  int *avir_sym;         /* relative alpha virtual index symmetry */
  int *bvir_sym;         /* relative beta virtual index symmetry */

  int *occ_off;       /* occupied orbital offsets within each irrep */
  int *aocc_off;      /* alpha occupied orbital offsets within each irrep */
  int *bocc_off;      /* beta occupied orbital offsets within each irrep */
  int *vir_off;       /* virtual orbital offsets within each irrep */
  int *avir_off;      /* alpha virtual orbital offsets within each irrep */
  int *bvir_off;      /* beta virtual orbital offsets within each irrep */
  int *cc_occ;        /* QT->CC active occupied reordering array */
  int *cc_aocc;       /* QT->CC alpha active occupied reordering array */
  int *cc_bocc;       /* QT->CC beta active occupied reordering array */
  int *cc_vir;        /* QT->CC active virtiual reordering array */
  int *cc_avir;       /* QT->CC alpha active virtiual reordering array */
  int *cc_bvir;       /* QT->CC beta active virtiual reordering array */
  int *qt_occ;        /* CC->QT active occupied reordering array */
  int *qt_aocc;       /* CC->QT alpha active occupied reordering array */
  int *qt_bocc;       /* CC->QT beta active occupied reordering array */
  int *qt_vir;        /* CC->QT active virtiual reordering array */
  int *qt_avir;       /* CC->QT alpha active virtiual reordering array */
  int *qt_bvir;       /* CC->QT beta active virtiual reordering array */

  int *pitzer2qt;     /* Pitzer -> QT translation array */
  int *qt2pitzer;     /* QT -> Pitzer translation array */

  int *pitzer2qt_a;   /* Pitzer -> QT translation array for alpha orbitals */
  int *qt2pitzer_a;   /* QT -> Pitzer translation array for alpha orbitals */
  int *pitzer2qt_b;   /* Pitzer -> QT translation array for beta orbitals */
  int *qt2pitzer_b;   /* QT -> Pitzer translation array for beta orbitals */

  int iter;              /* Current CCSD iteration */
  double conv;           /* Current convergence level */
  double enuc;           /* Nuclear repulsion energy */
  double emp2;           /* MP2 energy */
  double escf;           /* SCF energy (from chkpt) */
  double eref;           /* Reference energy (file100) */
  double ecc;            /* Current coupled cluster energy */
  double t1diag;         /* Standard open- or closed-shell T1 diagnostic */
  double d1diag;         /* Janssen and Nielsen's D1 Diagnostic */
  double new_d1diag;     /* Lee's modified D1 Diagnostic */
  double ***C;           /* Virtual orbital transformation matrix (for AO-basis B terms) */
  double ***Ca;          /* UHF alpha virtual orbital transformation matrix (for AO-basis B terms) */
  double ***Cb;          /* UHF beta virtual orbital transformation matrix (for AO-basis B terms) */
};
