<div dir="ltr"><div>It depends upon your system. In a dynamics on the electronic ground state ("Born-Oppenheimer" MD) your time step dt should be smaller than a fraction (let us say 1/10) of the inverse of the highest phonon frequency.<br></div></div><br><div class="gmail_quote"><div dir="ltr">On Tue, Jan 15, 2019 at 11:38 AM LEUNG Clarence <<a href="mailto:liangxy123@hotmail.com">liangxy123@hotmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
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<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<span style="color:rgb(33,33,33);font-family:"Microsoft Yahei UI",Verdana,Simsun,"Segoe UI",-apple-system,BlinkMacSystemFont,Roboto,"Helvetica Neue",sans-serif;font-size:14.6667px;background-color:rgb(255,255,255);display:inline">Dear
Giuseppe,</span><br>
</div>
<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<span style="color:rgb(33,33,33);font-family:"Microsoft Yahei UI",Verdana,Simsun,"Segoe UI",-apple-system,BlinkMacSystemFont,Roboto,"Helvetica Neue",sans-serif;font-size:14.6667px;background-color:rgb(255,255,255);display:inline"><br>
</span></div>
<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<span style="color:rgb(33,33,33);font-family:"Microsoft Yahei UI",Verdana,Simsun,"Segoe UI",-apple-system,BlinkMacSystemFont,Roboto,"Helvetica Neue",sans-serif;font-size:14.6667px;background-color:rgb(255,255,255);display:inline">Thanks
for your suggestion. </span></div>
<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<span style="color:rgb(33,33,33);font-family:"Microsoft Yahei UI",Verdana,Simsun,"Segoe UI",-apple-system,BlinkMacSystemFont,Roboto,"Helvetica Neue",sans-serif;font-size:14.6667px;background-color:rgb(255,255,255);display:inline">Can
MD in pw.x perform the simulation with dt = 1 fs ? </span></div>
<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<span style="color:rgb(33,33,33);font-family:"Microsoft Yahei UI",Verdana,Simsun,"Segoe UI",-apple-system,BlinkMacSystemFont,Roboto,"Helvetica Neue",sans-serif;font-size:14.6667px;background-color:rgb(255,255,255);display:inline"><br>
</span></div>
<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<span style="color:rgb(33,33,33);font-family:"Microsoft Yahei UI",Verdana,Simsun,"Segoe UI",-apple-system,BlinkMacSystemFont,Roboto,"Helvetica Neue",sans-serif;font-size:14.6667px;background-color:rgb(255,255,255);display:inline">LIANG
Xiongyi</span></div>
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<hr style="display:inline-block;width:98%">
<div id="gmail-m_8982360690130883907divRplyFwdMsg" dir="ltr"><font style="font-size:11pt" face="Calibri, sans-serif" color="#000000"><b>发件人:</b> users <<a href="mailto:users-bounces@lists.quantum-espresso.org" target="_blank">users-bounces@lists.quantum-espresso.org</a>> 代表 Giuseppe Mattioli <<a href="mailto:giuseppe.mattioli@ism.cnr.it" target="_blank">giuseppe.mattioli@ism.cnr.it</a>><br>
<b>发送时间:</b> 2019年1月15日 17:35<br>
<b>收件人:</b> <a href="mailto:users@lists.quantum-espresso.org" target="_blank">users@lists.quantum-espresso.org</a><br>
<b>主题:</b> Re: [QE-users] error in cp.x</font>
<div> </div>
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<div class="gmail-m_8982360690130883907BodyFragment"><font size="2"><span style="font-size:11pt">
<div class="gmail-m_8982360690130883907PlainText"><br>
Dear Liang Xiongyi<br>
<br>
There are a few things that should be changed in your input: for <br>
example dft-d3 is not implemented in cp.x., and nr(i)b=16 is a bit on <br>
the strict side (I generally use 20, but you should be sure that your <br>
value is insensitive to further change). However, dt=1 fs is a huge <br>
jump for CPMD and this is possibly the source of your <br>
orthonormalization error. You may try to use dt=1 a.u. for electronic <br>
minimization, and dt=3-6 a.u. for finite temperature runs. If you want <br>
to speed-up electronic minimization, then use pw.x and read the <br>
instructions for cp.x-pw.x interoperability to start a finite <br>
temperature CPMD from a ground state obtained by using pw.x. Remember <br>
also that, AFAIK, cppp.x is currently not usable for QE 6.3. You <br>
should write your own tool to analyze trajectories, as the prefix.pos <br>
output is written in a.u., too.<br>
HTH<br>
Giuseppe<br>
<br>
LEUNG Clarence <<a href="mailto:liangxy123@hotmail.com" target="_blank">liangxy123@hotmail.com</a>> ha scritto:<br>
<br>
> Dear QE Users,<br>
><br>
> When I use the cp.x to perform the thermal stability with dt = 1 fs, <br>
> an error occur:<br>
><br>
> <br>
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br>
> Error in routine ortho (1):<br>
> ortho went bananas<br>
> <br>
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br>
><br>
> stopping ...<br>
><br>
> And I have try to use short dt, it can works.<br>
><br>
> The input file is followed:<br>
><br>
> &CONTROL<br>
> etot_conv_thr = 3.5D-6 ,<br>
> forc_conv_thr = 4.0D-4 ,<br>
> ekin_conv_thr = 1d-4 ,<br>
> nstep = 20000 ,<br>
> tstress = .false. ,<br>
> tprnfor = .false. ,<br>
> dt=20.67,<br>
> isave = 100,<br>
> iprint = 10,<br>
> ndr = 51,<br>
> ndw = 51,<br>
> restart_mode = 'from_scratch',<br>
> verbosity = 'low' ,<br>
> /<br>
><br>
> &SYSTEM<br>
> ibrav=14,<br>
> celldm(1)=36.1187133640d0, celldm(2)=0.6119121863d0, <br>
> celldm(3)=1.3079965678d0,<br>
> celldm(4)=0.0000000000d0, celldm(5)=0.0000000000d0, <br>
> celldm(6)=0.0000000000d0,<br>
> nat=63,<br>
> ntyp=2,<br>
> ecutwfc=50,<br>
> ecutrho=400,<br>
> input_dft='PBE',<br>
> vdw_corr = 'DFT-D3' ,<br>
> nr1b = 16 ,<br>
> nr2b = 16 ,<br>
> nr3b = 16 ,<br>
> nosym = .true. ,<br>
> /<br>
> &ELECTRONS<br>
> emass = 400<br>
> emass_cutoff = 2.50,<br>
> electron_dynamics='damp',<br>
> electron_damping=0.2,<br>
> /<br>
> &IONS<br>
> ion_dynamics='none',<br>
> ion_radius(1)=1.0, ion_radius(2)=1.0,<br>
> /<br>
><br>
> ATOMIC_SPECIES<br>
> C 12.010700d0 C_pbe_v1.2.uspp.F.UPF<br>
> P 30.973800d0 P.pbe-n-rrkjus_psl.1.0.0.UPF<br>
><br>
> ATOMIC_POSITIONS {crystal}<br>
> P 0.207062953 0.994563394 0.532135751<br>
> P 0.042823633 0.994796583 0.465770116<br>
> C 0.157559602 0.119473623 0.509211511<br>
> C 0.092142096 0.120398444 0.486938482<br>
> P 0.453113260 0.016237452 0.533698293<br>
> P 0.289980002 0.986689982 0.464529400<br>
> C 0.399646081 0.133053286 0.505994952<br>
> C 0.335858066 0.117232823 0.482213070<br>
> P 0.704320783 0.007706925 0.532982064<br>
> P 0.538824580 0.008408401 0.468045855<br>
> C 0.654037234 0.132822314 0.511474768<br>
> C 0.587848371 0.135094109 0.489114957<br>
> P 0.956731588 -0.000006745 0.532145072<br>
> P 0.791554157 0.002228032 0.466394516<br>
> C 0.907495292 0.125510515 0.509696521<br>
> C 0.841931621 0.126642797 0.487430517<br>
> P 0.208266817 0.243782922 0.529541853<br>
> P 0.043965854 0.246589308 0.464392818<br>
> C 0.158728245 0.369838186 0.509463992<br>
> C 0.093217169 0.370873210 0.486709312<br>
> P 0.424177849 0.286343852 0.516852430<br>
> P 0.290089532 0.244400471 0.459582516<br>
> C 0.349540011 0.348792825 0.487513040<br>
> P 0.705574516 0.255089554 0.532107492<br>
> P 0.542012221 0.260506971 0.464249905<br>
> C 0.656129286 0.380833823 0.512136142<br>
> C 0.590214180 0.381152001 0.490082742<br>
> P 0.957108151 0.250073183 0.531244245<br>
> P 0.792998637 0.251922321 0.464998669<br>
> C 0.907321789 0.375462368 0.510050868<br>
> C 0.841746979 0.376334296 0.487596817<br>
> P 0.208402877 0.492352243 0.532960869<br>
> P 0.043963546 0.496372026 0.465432581<br>
> C 0.160144417 0.618157610 0.509696507<br>
> C 0.094342113 0.619600026 0.487659242<br>
> P 0.471073678 0.513328655 0.548894023<br>
> P 0.309129724 0.486227608 0.474070256<br>
> C 0.414925399 0.629235003 0.523346545<br>
> C 0.350961159 0.616373438 0.499640968<br>
> P 0.705395802 0.505478539 0.534378721<br>
> P 0.537192856 0.506995560 0.474222102<br>
> C 0.656825419 0.631333460 0.511436510<br>
> C 0.590845794 0.632466501 0.490389008<br>
> P 0.956482750 0.499986748 0.532254831<br>
> P 0.791270143 0.501641183 0.466922839<br>
> C 0.906923580 0.625196225 0.510129362<br>
> C 0.841214140 0.626345388 0.488309739<br>
> P 0.207667541 0.743674910 0.533472131<br>
> P 0.043998636 0.744658734 0.465730512<br>
> C 0.158052412 0.868776604 0.510578825<br>
> C 0.092761413 0.869723388 0.488195850<br>
> P 0.461194613 0.761061943 0.539728957<br>
> P 0.299530254 0.737206731 0.471960596<br>
> C 0.407654987 0.881987587 0.515312903<br>
> C 0.343486860 0.870097791 0.492007540<br>
> P 0.706175574 0.757137135 0.532107627<br>
> P 0.539960743 0.756974729 0.469099032<br>
> C 0.655720285 0.882343139 0.510585276<br>
> C 0.589586421 0.883272199 0.489712695<br>
> P 0.956945276 0.749651294 0.531828394<br>
> P 0.791991567 0.752132650 0.465926241<br>
> C 0.907222485 0.875386768 0.509910655<br>
> C 0.841486983 0.876756958 0.488249976<br>
><br>
> K_POINTS {gamma}<br>
><br>
> Thanks.<br>
><br>
> LIANG Xiongyi<br>
> City University of Hong Kong<br>
<br>
<br>
<br>
GIUSEPPE MATTIOLI<br>
CNR - ISTITUTO DI STRUTTURA DELLA MATERIA<br>
Via Salaria Km 29,300 - C.P. 10<br>
I-00015 - Monterotondo Scalo (RM)<br>
Mob (*preferred*) +39 373 7305625<br>
Tel + 39 06 90672342 - Fax +39 06 90672316<br>
E-mail: <<a href="mailto:giuseppe.mattioli@ism.cnr.it" target="_blank">giuseppe.mattioli@ism.cnr.it</a>><br>
<br>
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