Hi, You seemed to optimize your molecule in the presence of an external electric field. Once the field is turned on, the system's Hamiltonian is time (or step) dependent. I am not sure how the "optimized structure" is defined. <div class="gmail_quote">On Wed, Aug 11, 2010 at 2:51 PM, aarondesk <<a href="mailto:aaro...@gmail.com">aaro...@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Hello, I am trying to apply an external electrical field to a DFT (quickstep) calculation but am not having success. Please excuse my ignorance. I have tried with a simple test molecule - CO - that I want to apply an electrical field in the z direction. Below is my input (based off the regtest input). Unfortunately I get the same output whether the EFIELD section is present or not, which leads me to believe that no external field is being applied. Can you tell me what I'm doing wrong? Also, I have two other issues. The job crashes whenever START_STEP is set to 0 ("On entry to DLASCL parameter number 4 had an illegal value"), but 0 is the default value. Second, I don't quite understand the units for the field intensity. Manual says W/cm2, but if I convert this correctly, 5E15 W/cm2 = 3.77E11 V/angs which is huge. I just want an external field near 0.5 V/angs. Thank you, Aaron &FORCE_EVAL METHOD Quickstep &DFT UKS BASIS_SET_FILE_NAME ./GTH_BASIS_SETS_5-12-10 POTENTIAL_FILE_NAME ./GTH_POTENTIALS_5-12-10 WFN_RESTART_FILE_NAME x-RESTART.wfn &MGRID CUTOFF 300 &END MGRID &QS WF_INTERPOLATION ASPC EXTRAPOLATION_ORDER 3 &END QS &SCF EPS_SCF 1.E-6 SCF_GUESS RESTART MAX_SCF 400 &OT T PRECONDITIONER FULL_SINGLE_INVERSE MINIMIZER DIIS LINESEARCH 3PNT &END OT &END SCF &XC &XC_FUNCTIONAL PBE &END XC_FUNCTIONAL &END XC &PRINT &END PRINT &EFIELD INTENSITY 5E15 POLARISATION 0 0 1 #WAVELENGTH 210 ENVELOP CONSTANT &CONSTANT_ENV START_STEP 1 END_STEP 20 &END &END &END DFT &SUBSYS &CELL ABC 8.965 8.965 8.965 &END CELL &COORD SCALED F C 0.0 0.0 0.0 O 0.0 0.0 1.13 &END COORD &KIND O BASIS_SET TZVP-MOLOPT-GTH POTENTIAL GTH-PBE-q6 &END KIND &KIND C BASIS_SET TZVP-MOLOPT-GTH POTENTIAL GTH-PBE-q4 &END KIND &END SUBSYS &END FORCE_EVAL &GLOBAL PROJECT CO RUN_TYPE GEO_OPT PRINT_LEVEL LOW &END GLOBAL &MOTION &GEO_OPT MAX_ITER 200 MAX_FORCE 0.0009725 OPTIMIZER BFGS &END GEO_OPT -- You received this message because you are subscribed to the Google Groups "cp2k" group. To post to this group, send email to <a href="mailto:cp...@googlegroups.com">cp...@googlegroups.com</a>. To unsubscribe from this group, send email to <a href="mailto:cp2k%2Bun...@googlegroups.com">cp2k+uns...@googlegroups.com</a>. For more options, visit this group at <a href="http://groups.google.com/group/cp2k?hl=en" target="_blank">http://groups.google.com/group/cp2k?hl=en</a>. </blockquote></div>