Excited-State Methods in Q-Chem

TDDFT excited state analysis

Overview of Excited-State Capabilities

Q-Chem offers many excited-state methods, from CIS and TDDFT and their spin-flip variants to the high-level equation-of-motion coupled-cluster (EOM-CC) and the algebraic diagrammatic construction (ADC) methods. The table below summarizes excited-state methods available in Q-Chem.

Method Gradient Hessian
Configuration interaction singles
CIS
RPA
Extended (X)CIS
SF-XCIS
Spin-Adapted XCIS
CIS with perturbative doubles
CIS(D)
RI-CIS(D)
SOS-CIS(D)
SOS-CIS(D0)
Time-dependent DFT
TDDFT ✓* ✓*
Spin-Flip (SF) TDDFT
TDDFT with a Reduced Single-Excitation Space
∆SCF
MOM
ROKS with SGM
Non-orthogonal CI (NOCI)
NOCI
NOCIS/1C-NOCIS
Static Exchange (STEX)
Equation-of-motion coupled cluster theory (EOM-CC)
EOM-EE(SF)-CCSD** ✓***
EOM-IP(EA)-CCSD** ✓***
EOM-DIP(DEA)-CCSD**
EOM-CC/C-PCM
EOM-CCSD with Core-Valence Separation (CVS)
Algebraic diagrammatic construction (ADC)
RI-ADC
Spin Opposite Scaling ADC(2)
ADC with CVS
SF-ADC, IP-ADC, EA-ADC
ADC/SS-PCM
FDE-ADC
Restricted active space (RAS)
RAS-CI
RAS Spin-Flip (SF)

* Not for all exchange-correlation functionals.

** RI and CD variants are also available.

*** RHF and UHF reference only, including RI and CD implementations.



Properties and Analysis