Thank you Stefano for your prompt advise. I repeated the CP minimization commenting qcutz=150., q2sigma=2.0, ecfixed=24.0. I read that default value is ecfixed=40, which is larger than my cutoff for the wavefunction, then I guess that this does not affect the calculation. There is no much difference in the stress nor in the energy with respect to the calculation using qcutz=150., q2sigma=2.0, ecfixed=24.0.
I also changed the occupation to fixed with pwscf, and set ecfixed, qcutz and q2sigma. I also set ibrav=14 to match the CP job. The numbers with pw.x also change little change. Then I have a significant difference in the pressure of 29 kbar with pw vs -100 GPa with CP. Below is the summary of the last steps of CP miinimization with damped dynamics (I pasted it wrongly in the previous mail) nfi ekinc temph tempp etot enthal econs econt vnhh xnhh0 vnhp xnhp0 200 0.00772 0.0 0.0 -2096.99556 -2096.99556 -2096.99556 -2096.98785 0.0000 0.0000 0.0000 0.0000 writing restart file: .//cdte64_91.save restart file written in 24.895 sec. 201 0.00753 0.0 0.0 -2096.99846 -2096.99846 -2096.99846 -2096.99093 0.0000 0.0000 0.0000 0.0000 202 0.00735 0.0 0.0 -2097.00129 -2097.00129 -2097.00129 -2096.99394 0.0000 0.0000 0.0000 0.0000 203 0.00717 0.0 0.0 -2097.00405 -2097.00405 -2097.00405 -2096.99687 0.0000 0.0000 0.0000 0.0000 204 0.00700 0.0 0.0 -2097.00675 -2097.00675 -2097.00675 -2096.99974 0.0000 0.0000 0.0000 0.0000 205 0.00684 0.0 0.0 -2097.00938 -2097.00938 -2097.00938 -2097.00254 0.0000 0.0000 0.0000 0.0000 206 0.00668 0.0 0.0 -2097.01196 -2097.01196 -2097.01196 -2097.00527 0.0000 0.0000 0.0000 0.0000 207 0.00653 0.0 0.0 -2097.01447 -2097.01447 -2097.01447 -2097.00794 0.0000 0.0000 0.0000 0.0000 208 0.00638 0.0 0.0 -2097.01693 -2097.01693 -2097.01693 -2097.01055 0.0000 0.0000 0.0000 0.0000 209 0.00623 0.0 0.0 -2097.01934 -2097.01934 -2097.01934 -2097.01310 0.0000 0.0000 0.0000 0.0000 210 0.00609 0.0 0.0 -2097.02169 -2097.02169 -2097.02169 -2097.01559 0.0000 0.0000 0.0000 0.0000 211 0.00596 0.0 0.0 -2097.02399 -2097.02399 -2097.02399 -2097.01803 0.0000 0.0000 0.0000 0.0000 212 0.00582 0.0 0.0 -2097.02623 -2097.02623 -2097.02623 -2097.02041 0.0000 0.0000 0.0000 0.0000 213 0.00570 0.0 0.0 -2097.02843 -2097.02843 -2097.02843 -2097.02274 0.0000 0.0000 0.0000 0.0000 214 0.00557 0.0 0.0 -2097.03059 -2097.03059 -2097.03059 -2097.02501 0.0000 0.0000 0.0000 0.0000 215 0.00545 0.0 0.0 -2097.03269 -2097.03269 -2097.03269 -2097.02724 0.0000 0.0000 0.0000 0.0000 216 0.00533 0.0 0.0 -2097.03475 -2097.03475 -2097.03475 -2097.02942 0.0000 0.0000 0.0000 0.0000 217 0.00522 0.0 0.0 -2097.03677 -2097.03677 -2097.03677 -2097.03155 0.0000 0.0000 0.0000 0.0000 218 0.00511 0.0 0.0 -2097.03875 -2097.03875 -2097.03875 -2097.03364 0.0000 0.0000 0.0000 0.0000 219 0.00500 0.0 0.0 -2097.04068 -2097.04068 -2097.04068 -2097.03568 0.0000 0.0000 0.0000 0.0000 nfi ekinc temph tempp etot enthal econs econt vnhh xnhh0 vnhp xnhp0 220 0.00490 0.0 0.0 -2097.04257 -2097.04257 -2097.04257 -2097.03768 0.0000 0.0000 0.0000 0.0000 This was with the default values of ecfixed, etc. The corresponding pwscf energy (occupation=fixed) is -2097.047 Ha. Eduardo > > Today's Topics: > > 1. Re: (no subject) (degironc) > 2. Where to get CVS version of Q-Espresso? (Huiqun Zhou) > 3. Total number of d electrons of cobalt (Huiqun Zhou) > 4. Re: Where to get CVS version of Q-Espresso? (Miguel Martinez) > 5. Re: question about pwcond.x (Gabriel =?iso-8859-1?Q?Aut=E8s?=) > 6. Re: Total number of d electrons of cobalt (Matteo Cococcioni) > 7. Problem relaxing cluster (Lucas Fernandez Seivane) > 8. Re: Problem relaxing cluster (Silviu Zilberman) > > --__--__-- > > Message: 1 > Date: Wed, 15 Feb 2006 09:23:03 +0100 > From: degironc <degironc at sissa.it> > To: pw_forum at pwscf.org > Subject: Re: [Pw_forum] (no subject) > Reply-To: pw_forum at pwscf.org > > stress converges slowly with cutoff and if you are not at full > convergence > setting the variables qcutz=150., q2sigma=2.0, ecfixed=24.0, modifies > the kinetic energy > of the electrons beyond 24 ry adding a large penalty function and the > "effective" cutoff of your > calculation is something around 24 ry. > This affects the total energy and the stress. > Also having smearing instead of fixed occupation makes a difference but > > if your system is gapped it should not be large. > In order to compare output of the two codes you should use the same > setting in both. > > stefano > > > CP> > > > &SYSTEM > > ibrav = 14, > > celldm(1) = 24.4946, > > celldm(2) = 1.0,celldm(3) = 1.0,celldm(4) = > 0.0,celldm(5) = 0.0,celldm(6) = 0.0, > > nat = 64, > > ntyp = 2, > > nbnd=288,nelec=576,nspin=1, > > ecutwfc = 30.0 , > > ecutrho = 240 , > > occupations = 'fixed' , > > xc_type = 'PBE', > > > > qcutz=150., q2sigma=2.0, ecfixed=24.0, > > / > > > PW> > > > &SYSTEM > > ibrav = 1, > > celldm(1) = 24.4946, > > nat = 64, > > ntyp = 2, > > ecutwfc = 30.0 , > > ecutrho = 240 , > > occupations = 'smearing' , > > degauss = 0.02 , > > smearing = 'fermi-dirac' , > > / > > &ELECTRONS > > > > >
