7.9 Correlated Excited State Methods: The ADC(n) Family

7.9.10 Examples

Example 7.90  Input for an ADC(2)-s calculation of singlet exited states of methane with D2 symmetry. In total six excited states are requested corresponding to four (two) electronic transitions with irreducible representation B1 (B2).

$molecule
   0 1
   C
   H   1 r0
   H   1 r0   2  d0
   H   1 r0   2  d0   3  d1
   H   1 r0   2  d0   4  d1

   r0 = 1.085
   d0 = 109.4712206
   d1 = 120.0
$end

$rem
   METHOD              adc(2)
   BASIS               6-31g(d,p)
   MEM_TOTAL           4000
   MEM_STATIC          100
   EE_SINGLETS         [0,4,2,0]
$end

Example 7.91  Input for an unrestricted RI-ADC(2)-s calculation with C1 symmetry using DIIS. In addition, excited state properties and state-to-state properties are computed.

$molecule
   0 2
   C    0.0    0.0   -0.630969
   N    0.0    0.0    0.540831
$end

$rem
   METHOD           adc(2)
   BASIS            aug-cc-pVDZ
   AUX_BASIS        rimp2-aug-cc-pVDZ
   MEM_TOTAL        4000
   MEM_STATIC       100
   CC_SYMMETRY      false
   EE_STATES        6
   ADC_DO_DIIS      true
   ADC_PROP_ES      true
   ADC_PROP_ES2ES   true
   ADC_PROP_TPA     true
$end

Example 7.92  Input for a restricted CVS-ADC(2)-x calculation with C1 symmetry using 4 parallel CPU cores.

$molecule
   0 1
N         1.0706214490   -0.1462996030    0.0000000000
C        -0.1838756809    0.3832287690    0.0000000000
O        -1.2178351723   -0.2734201303    0.0000000000
H         1.8945772136    0.4351761203    0.0000000000
H         1.1761147729   -1.1515954431    0.0000000000
H        -0.1740335498    1.4879608698    0.0000000000
$end

$rem
   METHOD                      cvs-adc(2)-x
   EE_SINGLETS                 5
   ADC_DAVIDSON_MAXSUBSPACE    60
   MEM_TOTAL                   10000
   MEM_STATIC                  1000
   THREADS                     4
   CC_SYMMETRY                 false
   BASIS                       6-31G*
   ADC_DAVIDSON_THRESH         8
   SYMMETRY                    false
   ADC_DAVIDSON_MAXITER        900
   ADC_CVS                     true
   CC_REST_OCC                 4
$end

Example 7.93  Input for a restricted SF-ADC(2)-s calculation of the first three spin-flip target states of cyclobutadiene without point group symmetry.

$molecule
   0 3
   C     0.000000     0.000000     0.000000
   C     1.439000     0.000000     0.000000
   C     1.439000     0.000000     1.439000
   C     0.000000     0.000000     1.439000
   H    -0.758726     0.000000    -0.758726
   H     2.197726     0.000000    -0.758726
   H     2.197726     0.000000     2.197726
   H    -0.758726     0.000000     2.197726
$end

$rem
   METHOD          adc(2)
   MEM_TOTAL       15000
   MEM_STATIC      1000
   CC_SYMMETRY     false
   BASIS           3-21G
   SF_STATES       3
$end

The next example provides input for a restricted ADC(2)-x calculation of water with Cs symmetry. Four singlet A′′ excited states and two triplet A excited states are requested. For the first two states (1 A′′1 and 1 A3) the transition densities as well as the attachment and detachment densities are exported into cube files.

Example 7.94  Restricted ADC(2)-x calculation of water with Cs symmetry.

$molecule
   0 1
   O   0.000   0.000   0.000
   H   0.000   0.000   0.950
   H   0.896   0.000  -0.317
$end

$rem
   METHOD            adc(2)-x
   BASIS             6-31g(d,p)
   THREADS           2
   MEM_TOTAL         3000
   MEM_STATIC        100
   EE_SINGLETS       [0,4]
   EE_TRIPLETS       [2,0]
   ADC_PROP_ES       true
   MAKE_CUBE_FILES   true
$end

$plots
Plot transition and a/d densities
   40 -3.0 3.0
   40 -3.0 3.0
   40 -3.0 3.0
   0 0 2 2
   1 2
   1 2
$end

The next sample provides input for a ADC(2)-s/ptSS-PCM calculation of the five lowest singlet-excited states of N,N-dimethylnitroaniline in diethyl ether. The PCM settings are all default values except THEORY, which is set to IEFPCM instead of the default CPCM.

Example 7.95  DC(2)-s/ptSS-PCM calculation of N,N-dimethylnitroaniline in diethyl ether.

$molecule
   0 1
   C   -4.263068      2.512843      0.025391
   C   -5.030982      1.361365      0.007383
   C   -4.428196      0.076338     -0.021323
   C   -3.009941      0.019036     -0.030206
   C   -2.243560      1.171441     -0.011984
   C   -2.871710      2.416638      0.015684
   H   -4.740854      3.480454      0.047090
   H   -2.502361     -0.932570     -0.052168
   H   -1.166655      1.104642     -0.020011
   H   -6.104933      1.461766      0.015870
   N   -5.178541     -1.053870     -0.039597
   C   -6.632186     -0.969550     -0.034925
   H   -6.998203     -0.462970      0.860349
   H   -7.038179     -1.975370     -0.051945
   H   -7.001616     -0.431420     -0.910237
   C   -4.531894     -2.358860     -0.066222
   H   -3.912683     -2.476270     -0.957890
   H   -5.298508     -3.126680     -0.075403
   H   -3.902757     -2.507480      0.813678
   N   -2.070815      3.621238      0.033076
   O   -0.842606      3.510489      0.025476
   O   -2.648404      4.710370      0.054545
$end

$rem
   THREADS                4
   METHOD                 adc(2)
   BASIS                  3-21G
   MEM_TOTAL              32000
   MEM_STATIC             2000
   ADC_PROP_ES            true
   ADC_PRINT              1
   EE_SINGLETS            5
   ADC_DAVIDSON_MAXITER   100
   PCM_PRINT              1       !increase print level
   SOLVENT_METHOD         pcm     !invokes PCM solvent model
$end

$pcm
   nonequilibrium         true
   theory                IEFPCM  !default is CPCM, IEFPCM is more accurate
   Solver                Inversion
   vdwScale              1.20
$end

$solvent
   dielectric            4.34  !epsilon of Et2O
   dielectric_infi       1.829 !n_square of Et2O
$end

The next job requires a rather complicated compound input file. The sample job computes ADC/SS-PCM EqS solvent-field equilibration for the first excited singlet state of peroxinitrite in water, which can be used to compute the fluorescence energy. After generating a starting point in the first job (using a smaller basis and lower ADC convergence criteria), the solvent-field iterations are carried out until convergence in the second job. In the third job, ADC(2) excited states are computed in the converged solvent field that was left on disk by the second Job. In the fourth job, we additionally compute ADC(3) excited states. This mixed approach should in general be used with great caution. If the self-ptSS term of the reference state becomes too large (>0.01 eV) like it is the case here, the fully consistent approach should be used, meaning that the solvent reaction field should also be computed at the ADC(3) level. PCM settings are all default values except THEORY, which is set to IEFPCM instead of the default CPCM.

Example 7.96  ADC/SS-PCM EQS solvent-field equilibration for the first excited singlet state of peroxinitrite in water.

$comment
   ADC(2)/ptSS-PCM to generate starting point for the EqS
   Step in the next Job
$end

$molecule
   -1 1
   N    -0.068642000000     -0.600693000000     -0.723424000000
   O     0.349666000000      0.711166000000      1.187490000000
   O    -0.948593000000      0.200668000000     -0.956940000000
   O     0.659040000000     -0.386002000000      0.402650000000
$end

$rem
   THREADS             2
   METHOD              adc(2)
   BASIS               3-21G !using a small basis to speed up this step
   MEM_TOTAL           6000
   MEM_STATIC          1000
   EE_SINGLETS         1
   ADC_PROP_ES         true
   ADC_DAVIDSON_CONV   4
   SOLVENT_METHOD      pcm
$end

$pcm
   nonequilibrium true
$end

$solvent !Water
   dielectric       78.4
   dielectric_infi   1.76
$end


@@@


$comment
   ADC(2)/ptSS-PCM(EqS) solvent-field equilibration
   for the first excited state
$end

$molecule
   read
$end

$rem
   THREADS          2
   METHOD           adc(2)
   BASIS            6-31G*
   MEM_TOTAL        6000
   MEM_STATIC       1000
   EE_SINGLETS      2 !compute 2 singlets during the equilibration
   ADC_PROP_ES      true
   SOLVENT_METHOD   pcm !activate PCM
$end

$pcm
   eqsolv      15    !maximum 15 steps, converges after 5
   eqstate     1     !Equilibrate 1st excited state
   eqs_conv    4     !Default convergence
   theory      iefpcm
   nonequilibrium true
$end

$solvent
   dielectric       78.4
   dielectric_infi   1.76
$end


@@@


$comment
   Compute ADC(2) excited states in the converged solvent field
$end

$molecule
   read
$end

$rem
   THREADS          2
   METHOD           adc(2)
   BASIS            6-31G*
   MEM_TOTAL        6000
   MEM_STATIC       1000
   EE_SINGLETS      6 !compute 6 singlets
   ADC_PROP_ES      true
   ADC_PROP_ES2ES   true !compute ES 2 ES transition moments for ESA
   SOLVENT_METHOD   pcm
$end

$pcm
   eqsolv   true !only one calculation with converged field
   eqstate  1    !Equilibrate 1st excited state
   theory   iefpcm
   nonequilibrium true
$end

$solvent
   dielectric      78.4
   dielectric_infi  1.76
$end


@@@


$comment
   We can also compute ADC(3) excited states in the
   converged ADC(2) solvent field and use the self-
   ptSS term as diagnostic.
$end

$molecule
   read
$end

$rem
   THREADS          2
   METHOD           adc(3)
   BASIS            6-31G*
   MEM_TOTAL        6000
   MEM_STATIC       1000
   EE_SINGLETS      3 !compute 3 singlets
   EE_TRIPLETS      1    !and 1 triplet
   ADC_PROP_ES      true
   SOLVENT_METHOD   pcm
$end

$pcm
   eqsolv   true !only one calculation with converged field
   eqstate  1    !Equilibrate 1st excited state
   theory   iefpcm
   nonequilibrium true
$end

$solvent
   dielectric      78.4
   dielectric_infi  1.76
$end

The next sample job provides the input for a RI-ADC(2)/ptSS-PCM(PTED) calculation for the five lowest excited states of peroxinitrite in water. After generating a starting point in the first job, which also provides the ptSS(PTE) and ptSS(PTD) results for comparison, the solvent-field is equilibrated for the MP density in the second job. During the iterations, the calculation of excited states is disabled to speed up the calculation. In the third job, five excited states are computed at the RI-ADC(2)/ptSS(PTED) level of theory. Although the PTD corrections for this molecule are unusually large, a comparison of the PTE, PTD and PTD* results from the first job with the PTED results from the third job will reveal a reasonable agreement between the fully consistent PTED and the perturbative PTD approaches. In the fourth job, excited states are calculated with a larger basis set. The self-ptSS term of the MP ground state will be quite small, showing that the solvent-field computed with the smaller SVP basis is a good approximation.

Example 7.97  RI-ADC(2)/ptSS-PCM(PTED) calculation for the five lowest excited states of peroxinitrite in water.

$comment
   RI-ADC(2)/ptSS-PCM to generate starting point for
   the PTED iterations in the next Job and provide
   PTE and PTD energies for comparing with PTED
$end

$molecule
   -1 1
   N    -0.068642000000     -0.600693000000     -0.723424000000
   O     0.349666000000      0.711166000000      1.187490000000
   O    -0.948593000000      0.200668000000     -0.956940000000
   O     0.659040000000     -0.386002000000      0.402650000000
$end

$rem
   THREADS          2
   METHOD           adc(2)
   BASIS            def2-SVP
   AUX_BASIS        rimp2-VDZ
   MEM_TOTAL        6000
   MEM_STATIC       1000
   EE_SINGLETS      5
   ADC_PROP_ES      true
   SOLVENT_METHOD   pcm
$end

$pcm
   nonequilibrium true
$end

$solvent !Water
   dielectric      78.4
   dielectric_infi  1.76
$end


@@@


$comment
   RI-ADC(2)/ptSS-PTED solvent-field equilibration for
   the MP ground state. No excited states are computed
$end

$molecule
   read
$end

$rem
   THREADS          2
   METHOD           adc(2)
   BASIS            def2-SVP
   AUX_BASIS        rimp2-VDZ
   MEM_TOTAL        6000
   MEM_STATIC       1000
   EE_SINGLETS      0 !dont compute ES
   ADC_PROP_ES      true
   SOLVENT_METHOD   pcm !activate PCM
$end

$pcm
   eqsolv     15    !maximum 15 steps
   eqstate    0     !Equilibrate MP ground state
   eqs_conv   5     !higher convergence
   theory     iefpcm
   nonequilibrium true
$end

$solvent
   dielectric      78.4
   dielectric_infi  1.76
$end


@@@


$comment
   Compute ADC(2)/ptSS-PTED excited states in the
   converged solvent field
$end

$molecule
   read
$end

$rem
   THREADS          2
   METHOD           adc(2)
   BASIS            def2-SVP
   AUX_BASIS        rimp2-VDZ
   MEM_TOTAL        6000
   MEM_STATIC       1000
   EE_SINGLETS      5 !compute 5 singlets
   ADC_PROP_ES      true
   SOLVENT_METHOD   pcm
$end

$pcm
   eqsolv   true !only one calculation with converged field
   eqstate  0    !Equilibrate MP ground state
   theory   iefpcm
   nonequilibrium true
$end

$solvent
   dielectric 78.4
   dielectric_infi 1.76
$end


@@@


$comment
   We can also compute the ES in the converged field
   with a larger basis and without RI in the stored
   solvent-field.
$end

$molecule
   read
$end

$rem
   THREADS         2
   METHOD          adc(2)
   BASIS           def2-TZVP
   MEM_TOTAL       6000
   MEM_STATIC      1000
   EE_SINGLETS     3 !compute 3 singlets
   ADC_PROP_ES     true
   SOLVENT_METHOD  pcm
$end

$pcm
   eqsolv  true !only one calculation with converged field
   eqstate 0  !Equilibrate MP ground state
   theory iefpcm
   nonequilibrium true
$end

$solvent
   dielectric 78.4
   dielectric_infi 1.76
$end