ASR is applied by auxiliary code, confusingly named "matdyn.x" and "dynmat.x"
Paolo On Mon, Sep 14, 2020 at 9:42 AM Offermans Willem <willem.offerm...@vito.be> wrote: > Dear QE friends and Paolo, > > I’m sorry to break into this mail thread, but could you elaborate a bit on > “applying acoustic sum rule”. > > How is this done? > > > > Met vriendelijke groeten, > Mit freundlichen Grüßen, > With kind regards, > > > Willem Offermans > Researcher Electrocatalysis SCT > VITO NV | Boeretang 200 | 2400 Mol > Phone:+32(0)14335263 Mobile:+32(0)492182073 > > willem.offerm...@vito.be > > > On 14 Sep 2020, at 08:34, Paolo Giannozzi <p.gianno...@gmail.com> wrote: > > Apparently the largest discrepancies come from low-energy modes, in > particular zero-frequency acoustic modes (those with "negative" frequencies > that become zero when acoustic sum rule is applied). Even minor changes in > the way exchange-correlation is computed may lead to surprisingly large but > unphysical differences for those modes. > > Paolo > > On Sun, Sep 13, 2020 at 7:54 PM Unmesh Mondal < > unmesh.mon...@students.iiserpune.ac.in> wrote: > >> Dear all, >> I intend to calculate the vibrational modes of gas phase HCOOH (formic >> acid) molecule. >> >> The "ph.x" vibrational frequencies (in cm-1) of the system for the two >> versions of quantum espresso (6.5 and 6.4 : with same compilers) are: >> (QE 6.5) (QE 6.4) >> 1 -207.654081 -207.686563 >> 2 -63.775769 -61.840758 >> 3 -55.090067 -57.158594 >> 4 -15.183543 -15.903109 >> 5 20.311666 21.386665 >> 6 129.683418 129.214185 >> 7 615.352300 615.209434 >> 8 676.597853 676.547298 >> 9 999.285772 999.331118 >> 10 1071.840671 1071.779138 >> 11 1253.496419 1253.514267 >> 12 1350.618940 1350.925730 >> 13 1735.698557 1735.582574 >> 14 2965.285270 2965.885980 >> 15 3665.961548 3665.948232 >> >> The maximum difference in any frequency for the two versions is about 2 >> cm-1. My question: >> Is the difference of 2 cm-1 within the error limit of ph.x >> calculations? What is the accuracy we expect in reporting the vibrational >> frequency (via ph.x)? >> >> Regards and Thanks >> Unmesh Mondal >> IISER Pune, India >> >> _______________________________________________ >> Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso >> <https://eur02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.max-centre.eu%2Fquantum-espresso&data=02%7C01%7C%7Ceb09c593764540a31b7d08d858786b5c%7C9e2777ed82374ab992782c144d6f6da3%7C0%7C0%7C637356621508435090&sdata=kTKqeX%2F%2F%2BO6kPNwef4FIkRfJEGe0%2F%2BN3PfxwhTEI0vM%3D&reserved=0> >> ) >> users mailing list users@lists.quantum-espresso.org >> https://lists.quantum-espresso.org/mailman/listinfo/users >> <https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.quantum-espresso.org%2Fmailman%2Flistinfo%2Fusers&data=02%7C01%7C%7Ceb09c593764540a31b7d08d858786b5c%7C9e2777ed82374ab992782c144d6f6da3%7C0%7C0%7C637356621508445049&sdata=3H9VxidE80u1fJGpErn5ia73gcU1wHWEO%2BBKUGsKTEo%3D&reserved=0> > > > > -- > Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, > Univ. Udine, via delle Scienze 208, 33100 Udine, Italy > Phone +39-0432-558216, fax +39-0432-558222 > > _______________________________________________ > Quantum ESPRESSO is supported by MaX ( > https://eur02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.max-centre.eu%2Fquantum-espresso&data=02%7C01%7C%7Ceb09c593764540a31b7d08d858786b5c%7C9e2777ed82374ab992782c144d6f6da3%7C0%7C0%7C637356621508464957&sdata=Ve%2ByVOhyxj96wsoUv84X01T7RhUF%2BsbovgeiBIRDERA%3D&reserved=0 > ) > users mailing list users@lists.quantum-espresso.org > > https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.quantum-espresso.org%2Fmailman%2Flistinfo%2Fusers&data=02%7C01%7C%7Ceb09c593764540a31b7d08d858786b5c%7C9e2777ed82374ab992782c144d6f6da3%7C0%7C0%7C637356621508464957&sdata=35lAnSluB8%2BFUxrP7RLiFDVqfOKa7Qs7Xi94ZtlXEq0%3D&reserved=0 > > > VITO Disclaimer: http://www.vito.be/e-maildisclaimer > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) > users mailing list users@lists.quantum-espresso.org > https://lists.quantum-espresso.org/mailman/listinfo/users -- Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222
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