Dear Guido I really appreciate for your reply,which helps me a lot in understanding Local DOS,and I've understood it, thank you very much! 朱林光 > -----原始邮件----- > 发件人: "Guido Fratesi" <[email protected]> > 发送时间: 2017-02-14 21:37:24 (星期二) > 收件人: "PWSCF Forum" <[email protected]>, "朱林光" <[email protected]> > 抄送: > 主题: Re: [Pw_forum] How to understand Local DOS of a certain atom in qe example > > Dear 朱林光, > > volumes are defined as boxes with edges parallel to the unit cell, > containing the points of the (charge density) FFT grid included within > irmin and irmax, in the three dimensions: from irmin(j,n) to irmax(j,n) > for j=1,2,3 (n=1,n_proj_boxes). Let me try to be specific with that example: > > > From the output of pw.x: > > lattice parameter (alat) = 7.4246 a.u. > > crystal axes: (cart. coord. in units of alat) > a(1) = ( 1.000000 0.000000 0.000000 ) > a(2) = ( 0.000000 1.414214 0.000000 ) > a(3) = ( 0.000000 0.000000 6.000000 ) > > Dense grid: 24607 G-vectors FFT dimensions: ( 18, 25, 108) > > > Positions in the real-space unit cell can be measured in units of alat, > or of bohr, or of ..., or of points along the axes as is done here: For > example, irmin(3,1)=63 and irmax(3,1)=65 means that the first box, along > the z-axis, extends from the 63th point to the 65th of the real-space > mesh, out of 108 FFT points total. > > The spacing between points along the z-coordinate (a(3) axis) is > (6.000000*7.4246 a.u.)/108. > > Similarly for x,y coordinates specified by irmin/max(1,*), and > irmin/max(2,*) with 18 and 25 mesh points, respectively. > > Hope this helps, > > Guido > > > > > > On 13/02/2017 15:04, 朱林光 wrote: > > Dear all qe users: > > I have a problem of understanding Local DOS of a certain atom in qe > > example,especially the term irmin(*,*) and irmax in the following input > > file,I don't understand why and how we can do the LDOS calculations of a > > certain atom only by defining the value of irmin and irmax?especially how > > can we use the value of irmin to specify the LDOS we are going to calculate > > is above the surface Al not above the surface As? for example irmin(1,1)= > > 0, irmax(1,1)= 2, irmin(2,1)= 0, irmax(2,1)= 2, irmin(3,1)=63, > > irmax(3,1)=65, > > &projwfc > > prefix = 'AlAs110' > > outdir='$TMP_DIR/', > > ngauss=0 > > degauss=0.01 > > DeltaE=0.02 > > tdosinboxes=.true. > > plotboxes=.true. > > n_proj_boxes=8 > > > > !! Boxes centered on the first vacuum layer: > > !! 1) above the surface Al > > irmin(1,1)= 0, irmax(1,1)= 2, irmin(2,1)= 0, irmax(2,1)= 2, > > irmin(3,1)=63, irmax(3,1)=65, > > !! 2) above the surface As > > irmin(1,2)= 9, irmax(1,2)=11, irmin(2,2)= 5, irmax(2,2)= 7, > > irmin(3,2)=63, irmax(3,2)=65, > > !! 3) above the 2nd layer Al > > irmin(1,3)= 9, irmax(1,3)=11, irmin(2,3)=14, irmax(2,3)=16, > > irmin(3,3)=63, irmax(3,3)=65, > > !! 4) as large as the surface unit cell > > irmin(1,4)= 1, irmax(1,4)=18, irmin(2,4)= 1, irmax(2,4)=27, > > irmin(3,4)=63, irmax(3,4)=65, > > > > !! Same as above, centered on the second vacuum layer: > > irmin(1,5)= 0, irmax(1,5)= 2, irmin(2,5)= 0, irmax(2,5)= 2, > > irmin(3,5)=72, irmax(3,5)=74, > > irmin(1,6)= 9, irmax(1,6)=11, irmin(2,6)= 5, irmax(2,6)= 7, > > irmin(3,6)=72, irmax(3,6)=74, > > irmin(1,7)= 9, irmax(1,7)=11, irmin(2,7)=14, irmax(2,7)=16, > > irmin(3,7)=72, irmax(3,7)=74, > > irmin(1,8)= 1, irmax(1,8)=18, irmin(2,8)= 1, irmax(2,8)=27, > > irmin(3,8)=72, irmax(3,8)=74, > > / > > > > -- > Guido Fratesi > > Dipartimento di Fisica > Universita` degli Studi di Milano > Via Celoria 16, 20133 Milano, Italy >
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