List of quantum chemistry abbreviations is very useful for starting theoreticians and especially for experimentalists who need to read a quantum chemistry paper.

AO - atomic orbital

CAS - complete active space

CASSCF - complete active space self-consistent-field

CCSD - coupled-cluster theory with single and double excitations

CI - configuration interaction

CISD - configuration interaction with single and double excitations

CLSCF - closed-shell self-consistent-field

CSF - configuration stat function

DFT - density functional theory

DIIS - Direct Inversion in the Iterative Subspace

DM - Direct Minimization


EOM - equation of motion

EA - electron attachement

GDM - geometric direct minimization

GTO - Gaussian-type orbital

GVB - generalized valence bond

HF - Hartree-Fock

HOMO - highest occupied molecular orbital

IP - ionization potential

LCAO - linear combination of atomic orbitals

LUMO - lowest unoccupied molecular orbital

MO - molecular orbital

MOM - maximum overlap method

MCSCF - multiconfiguration self-consitent-field

MP2 - second-order Møller-Plesset perturbation theory

NBO - natural bond orbital

NBO - non-bonding orbital

NVT - nuclear vibrational theory

OO - optimized orbital

PES - potential energy surface

RHF - restricted Hartree-Fock

ROHF - restricted open shell Hartree-Fock

SCF - self-constistent-field

SF - spin flip

STO - Slater-type orbital

TDDFT - time–dependent density functional theory

TOSH - transition–optimized shifted Hermite

TZ - triple zeta

UHF - unrestricted Hartree-Fock

VCI - vibrational configuration interaction

VPT2 - second–order vibrational perturbation theory

ZPE - zero point energy

If you have any additions to this list please fill free to commnet on that.