General: **RESPONSE

General-purpose directives are given in the **RESPONSE section.

After the last directive of the **RESPONSE input group should follow another **<something> input group (or **END OF DALTON INPUT if this was the last input to DALTON).

.HIRPA INVOKE THE HIGHER RPA APPROXIMATION FOR THE CALCULATION OF LINEAR RESPONSE PROPERTIES. THIS APPROXIMATION IS IDENTICAL TO THAT OF MCKOY AND COWORKERS [,]. THE REQUIREMENTS TO THE PRECEDING WAVE FUNCTION CALCULATION IS THE SAME AS FOR THE .SOPPA KEYWORD. THIS KEYWORD OVERRIDES A SIMULTANEOUS SPECIFICATION OF .SOPPA.

.INPTEST INPUT TEST. FOR DEBUGGING PURPOSES ONLY. THE PROGRAM STOPS AFTER THE INPUT SECTION.

.MAXPHP
READ *, MAXPHP
CHANGE THE MAXIMUM DIMENSION OF SUBSPACE. DEFAULT IS 100. PHP IS A SUBBLOCK OF THE CI MATRIX WHICH IS CALCULATED EXPLICITLY IN ORDER TO OBTAIN IMPROVED CI TRIAL VECTORS COMPARED TO THE STRAIGHT DAVIDSON ALGORITHM[159]. THE CONFIGURATIONS CORRESPONDING TO THE LOWEST DIAGONAL ELEMENTS ARE SELECTED, UNLESS .PHPRESIDUAL IS SPECIFIED. MAXPHP IS THE MAXIMUM DIMENSION OF PHP, THE ACTUAL DIMENSION WILL BE LESS IF MAXPHP WILL SPLIT DEGENERATE CONFIGURATIONS.

.MAXRM
READ *, MAXRM
CHANGE THE MAXIMUM DIMENSION OF THE REDUCED SPACE. DEFAULT IS 200. WHEN SOLVING A LINEAR SYSTEM OF EQUATIONS OR AN EIGENVALUE EQUATION, THE REDUCED SPACE IS INCREASED BY THE NUMBER OF FREQUENCIES/EXCITATIONS IN EACH ITERATION. FOR SINGLE ROOT CALCULATIONS THIS SHOULD EXCEED THE NUMBER OF ITERATIONS REQUIRED. MAXRM SHOULD BE INCREASED IF MANY FREQUENCIES OR EXCITATION ENERGIES ARE TO BE CALCULATED. SHARP CONVERGENCE THRESHOLDS ALSO REQUIRE MORE ITERATIONS AND THUS LARGER DIMENSION OF THE REDUCED SPACE.

.NOAVDI DO NOT USE FOCK TYPE DECOUPLING OF THE TWO-ELECTRON DENSITY MATRIX. ADD INSTEAD OF TO APPROXIMATE ORBITAL DIAGONAL. NOT RECOMMENDED AS THE APPROXIMATE ORBITAL DIAGONAL NORMALLY WILL BECOME MORE DIFFERENT FROM THE EXACT ORBITAL DIAGONAL.

.NODOIT TURNS OFF DIRECT ONE-INDEX TRANSFORMATION [160]. IN THIS WAY ALL ONE-INDEX TRANSFORMED INTEGRALS ARE STORED ON DISK.

.NOITRA NO INTEGRAL TRANSFORMATION. NORMALLY THE TWO-ELECTRON INTEGRALS ARE TRANSFORMED IN THE BEGINNING OF A RESPONSE CALCULATION. IN SOME CASES THIS IS NOT DESIRABLE, E.G., IF THE RESPONSE PART IS ONLY USED FOR CALCULATING AVERAGE VALUES OF AN OPERATOR, OR IF THE TRANSFORMED TWO-ELECTRON INTEGRALS ALREADY EXIST FROM A PREVIOUS RESPONSE CALCULATION.

.OPTORB ORBITAL TRIAL VECTORS ARE CALCULATED WITH OPTIMAL ORBITAL TRIAL VECTOR ALGORITHM [21].

.ORBSFT
READ *, ORBSFT
CHANGE THE AMOUNT FOR SHIFTING THE ORBITAL DIAGONAL OF THE MCSCF HESSIAN. MAY BE USED IF THERE IS A LARGE NUMBER OF NEGATIVE EIGENVALUES. DEFAULT IS .

.ORBSPC CALCULATION WITH ONLY ORBITAL OPERATORS.

.PHPRESIDUAL SELECT CONFIGURATIONS FOR PHP MATRIX BASED ON LARGEST RESIDUAL RATHER THAN LOWEST DIAGONAL ELEMENTS.

.SOPPA REQUESTS THE SECOND ORDER POLARIZATION PROPAGATOR APPROXIMATION IN THE LINEAR RESPONSE MODULE. THE SOPPA FLAG REQUIRES THAT THE PRECEDING SIRIUS CALCULATION HAS GENERATED THE MP2 CORRELATION COEFFICIENTS AND WRITTEN THEM TO DISK (SET .RUN RESPONSE IN **DALTON INPUT AS WELL AS .HF AND .MP2 IN **WAVE FUNCTIONS). SEE EXAMPLE INPUT IN CHAPTER .

.PROPAV
READ '(A)', LABEL
PROPERTY AVERAGE. THE AVERAGE VALUE OF AN ELECTRONIC ONE-ELECTRON OPERATOR IS CALCULATED. (THUS, NO NUCLEAR CONTRIBUTIONS ARE ADDED.) THE LINE FOLLOWING THIS OPTION MUST CONTAIN THE LABEL OF THE OPERATOR GIVEN IN THE INTEGRAL PROPERTY FILE. (SEE SECTION .)

.QRREST RESTART QUADRATIC RESPONSE CALCULATION. REQUIRES THAT ALL NEEDED LINEAR RESPONSE SOLUTIONS AND EXCITATION VECTORS ARE AVAILABLE ON THE RSPVEC FILE.

.S0MIX SUM RULE IS CALCULATED IN MIXED REPRESENTATION, THAT IS, CALCULATE #MATH1170# PROVIDED THAT DIPOLE LENGTH AND VELOCITY INTEGRALS ARE AVAILABLE ON THE PROPERTY INTEGRAL FILE (CALCULATED WITH **HERMIT OPTIONS .DIPLEN AND .DIPVEL). THE CALCULATED QUANTITY GIVES A MEASURE OF THE QUALITY OF THE BASIS SET.

.SOPPA(CCSD) REQUESTS THE SECOND ORDER POLARIZATION PROPAGATOR APPROXIMATION WITH COUPLED CLUSTER SINGLES AND DOUBLES AMPLITUDES IN THE LINEAR RESPONSE MODULE. THE SOPPA(CCSD) FLAG REQUIRES THAT THE PRECEDING COUPLED CLUSTER CALCULATION HAS GENERATED THE CCSD AMPLITUDES AND WRITTEN THEM TO DISK (SET .RUN RESPONSE IN **DALTON INPUT, .HF AND .CC IN **WAVE FUNCTIONS AND .SOPPA(CCSD) IN *CC INPUT). SEE EXAMPLE INPUT IN CHAPTER .

.SOPW4 CALCULATE EXPLICITLY THE W4 TERM DESCRIBED BY ODDERSHEDE ET AL. [49]. THIS TERM IS ALREADY INCLUDED IN THE NORMAL SOPPA OR SOPPA(CCSD) RESULT, AND USED MOSTLY FOR COMPARING TO OLDER CALCULATIONS. NOTE THAT THIS KEYWORD REQUIRES THAT .SOPPA OR .SOPPA(CCSD)IS SET.

.TRPFLG TRIPLET FLAG. THIS OPTION IS SET WHENEVER TRIPLET (SPIN-DEPENDENT) OPERATORS MUST BE USED IN A RESPONSE CALCULATION [,]. THIS FLAG FORCES TRIPLET LINEAR RESPONSE FOR *LINEAR, BOTH FOR SECOND ORDER PROPERTIES AND ELECTRONIC EXCITATIONS (WITHOUT AND WITH .SINGLE RESIDUE).