You can use the CELL_PARAMETERS card with ibrav=0 (so no need to compute the angles) or directly use the definition of celldm(4), celldm(5), celldm(6) with ibrav=14 from Doc/INPUT_PW.txt:
celldm(4)= cos(bc) b —> -0.004621093 2.150980697 0.080635052 c —> -0.031624028 0.077886584 1.892891072 celldm(4) = 0.0785376 celldm(5)= cos(ac)=0.0165872 celldm(6)=cos(ab)=-0.00341855 Giovanni > > On 20 Nov 2015, at 11:19, Francesco Pelizza <[email protected]> > wrote: > > Hi dear Users and Developers, > > I really need a full explanation on how to get Celldm(4) Celldm(5) > Celldm(6) from a VC-relaxation. > > The optimized structure of a system with angles between a-lat b-lat a > c-lat not equals to 90° is given to me in some systems I am studying, > > But I can not find a way of putting this in a new input file. > > If I masure with xcrysden the inclination between periodic images, I got > an angle that if i translate in the cosine value and put it into the > input file, it does not give me the right angle when I open again the > input file with xcrysden. > Also a SCF calculation does not give a value identical or not even > slightly different from the VC-rel calculation itself. > > So, How can I find out exactly Celldm(4) Celldm(5) Celldm(6) from this > piece of output file? > > How do I put this in an input file being sure that quantum espresso will > consider this value for building the lattice and doing the calculation > properly ?? > > Thank you very much for your time and patience > > Francesco Pelizza - PhD > Strathclyde University (Glasgow) > > HERE you can find an output file as example > > > Begin final coordinates > new unit-cell volume = 3435.21521 a.u.^3 ( 509.04637 Ang^3 ) > > CELL_PARAMETERS (alat= 9.35454172) > 1.031703302 -0.002607611 0.034483284 > -0.004621093 2.150980697 0.080635052 > -0.031624028 0.077886584 1.892891072 > > ATOMIC_POSITIONS (angstrom) > H 2.323443642 3.458500775 8.048639166 > H 2.246157109 6.259499847 5.493082766 > H 2.238584163 4.257844190 0.859706518 > H 3.682576551 4.461248011 7.513953456 > H 3.660946840 5.289309420 5.076217107 > H 2.349858362 7.288089944 3.177035899 > H 3.698019711 6.240499825 2.728594264 > H 3.699705365 5.164845115 0.461710112 > F 2.578959296 7.555136884 0.769673740 > F 0.723629375 6.423372715 1.255939854 > F 2.384732674 3.966152941 3.106747236 > F 0.653462109 5.273905894 3.651911386 > F 2.644696706 2.964473519 5.656123191 > F 0.735387849 4.041727492 6.056045010 > F 0.629819356 5.581707632 8.226678603 > F 2.449175259 6.758487891 7.688004312 > F 4.791542403 2.350295723 2.918699000 > F 5.145230100 1.372558160 5.464114891 > H 3.794899005 0.874565766 1.033564982 > H 3.767987315 0.169480940 8.124815255 > F 1.620809549 1.343881537 2.353960638 > H 0.055376396 1.880995718 0.351068538 > F 1.746935882 0.059135078 4.717276882 > H 0.118749183 1.089942064 7.543474278 > H 0.038360119 8.721213695 5.604899727 > H 0.156416543 9.733931543 3.301761239 > F 1.606381831 9.555176644 7.542110410 > F 1.724803088 10.423382736 0.580085061 > H 3.762597275 9.742742557 6.180086748 > H 3.818806059 10.647160213 3.895291475 > F 4.834332727 8.431554403 8.190079715 > F 5.022683471 9.219462377 1.286641665 > C 4.861902815 0.149655116 8.161361938 > C 4.884761682 0.947642455 1.045408665 > C 0.337188869 0.143176054 4.742567438 > C 0.232687916 1.146022481 2.332101032 > C 2.593624135 4.380706568 7.522390456 > C 2.129082034 4.198114186 6.068998645 > C 2.035262317 5.577048626 8.307268734 > C 2.567916441 5.297168460 5.092510941 > C 2.062790705 5.205690370 3.651450062 > C 2.607997073 5.181809062 0.410338732 > C 2.124256003 6.343778231 1.286849130 > C 2.609613700 6.314467444 2.746950137 > C 0.204140831 9.649137133 7.505914552 > C 0.317897336 10.413912382 0.493174549 > C 4.910634377 10.672243764 3.875929892 > C 4.854146045 9.672373698 6.207264609 > End final coordinates > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum -- Giovanni Cantele, PhD CNR-SPIN c/o Dipartimento di Fisica Universita' di Napoli "Federico II" Complesso Universitario M. S. Angelo - Ed. 6 Via Cintia, I-80126, Napoli, Italy e-mail: [email protected] Phone: +39 081 676910 Skype contact: giocan74 ResearcherID: http://www.researcherid.com/rid/A-1951-2009 Web page: http://people.na.infn.it/~cantele _______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
