Dear Elaine, Thank you for reply.
"If you want to study a pair of interstitial N atoms, you must add two N atoms, not replace P. Or if you are replacing P by two interstitial N atoms, you remove one P and add two N at new positions". "Are you trying to add an interstitial N2 molecule? If not why do you need two N atoms?" Yes, I am trying to replace P atom by N2 molecule bounded with Ga atoms (each N atom is bounded with 2 Ga atoms). So, I remove one P atom and add two symmetrically shifted N atoms (with respect to the P atom position). "If the reduced cell has 16 inequivalent atoms, it sounds as though you have 64 not 65 atoms" No, I have 65 atoms: 32 Ga atoms, 31 P atoms and 2 N atoms. Here is my structure file. GaAs P 10 215 P-43m RELA 21.353914 21.353914 21.353914 90.000000 90.000000 90.000000 ATOM 1: X=0.00000000 Y=0.00000000 Z=0.00000000 MULT= 1 ISPLIT= 2 B 1 NPT= 781 R0=0.00005000 RMT= 1.6500 Z: 5.00000 LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 0.0000000 1.0000000 0.0000000 0.0000000 0.0000000 1.0000000 ATOM -2: X=0.50000000 Y=0.00000000 Z=0.00000000 MULT= 3 ISPLIT=-2 -2: X=0.00000000 Y=0.50000000 Z=0.00000000 -2: X=0.00000000 Y=0.00000000 Z=0.50000000 Ga1 NPT= 781 R0=0.00005000 RMT= 2.0000 Z: 31.00000 LOCAL ROT MATRIX: 0.0000000 0.0000000 1.0000000 1.0000000 0.0000000 0.0000000 0.0000000 1.0000000 0.0000000 ATOM -3: X=0.50000000 Y=0.50000000 Z=0.00000000 MULT= 3 ISPLIT=-2 -3: X=0.00000000 Y=0.50000000 Z=0.50000000 -3: X=0.50000000 Y=0.00000000 Z=0.50000000 Ga2 NPT= 781 R0=0.00005000 RMT= 2.0000 Z: 31.00000 LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 0.0000000 1.0000000 0.0000000 0.0000000 0.0000000 1.0000000 ATOM 4: X=0.50000000 Y=0.50000000 Z=0.50000000 MULT= 1 ISPLIT= 2 Ga3 NPT= 781 R0=0.00005000 RMT= 2.0000 Z: 31.00000 LOCAL ROT MATRIX: 1.0000000 0.0000000 0.0000000 0.0000000 1.0000000 0.0000000 0.0000000 0.0000000 1.0000000 ATOM -5: X=0.24565249 Y=0.24565249 Z=0.00018192 MULT=12 ISPLIT= 8 -5: X=0.75434751 Y=0.75434751 Z=0.00018192 -5: X=0.75434751 Y=0.24565249 Z=0.99981808 -5: X=0.24565249 Y=0.75434751 Z=0.99981808 -5: X=0.00018192 Y=0.24565249 Z=0.24565249 -5: X=0.00018192 Y=0.75434751 Z=0.75434751 -5: X=0.99981808 Y=0.75434751 Z=0.24565249 -5: X=0.99981808 Y=0.24565249 Z=0.75434751 -5: X=0.24565249 Y=0.00018192 Z=0.24565249 -5: X=0.75434751 Y=0.00018192 Z=0.75434751 -5: X=0.24565249 Y=0.99981808 Z=0.75434751 -5: X=0.75434751 Y=0.99981808 Z=0.24565249 Ga4 NPT= 781 R0=0.00005000 RMT= 2.0000 Z: 31.00000 LOCAL ROT MATRIX: 0.0000000-0.7071068-0.7071068 0.0000000-0.7071068 0.7071068 -1.0000000 0.0000000 0.0000000 ATOM -6: X=0.24997050 Y=0.49992725 Z=0.24997050 MULT=12 ISPLIT= 8 -6: X=0.75002950 Y=0.50007275 Z=0.24997050 -6: X=0.75002950 Y=0.49992725 Z=0.75002950 -6: X=0.24997050 Y=0.50007275 Z=0.75002950 -6: X=0.24997050 Y=0.24997050 Z=0.49992725 -6: X=0.24997050 Y=0.75002950 Z=0.50007275 -6: X=0.75002950 Y=0.75002950 Z=0.49992725 -6: X=0.75002950 Y=0.24997050 Z=0.50007275 -6: X=0.49992725 Y=0.24997050 Z=0.24997050 -6: X=0.50007275 Y=0.24997050 Z=0.75002950 -6: X=0.49992725 Y=0.75002950 Z=0.75002950 -6: X=0.50007275 Y=0.75002950 Z=0.24997050 Ga5 NPT= 781 R0=0.00005000 RMT= 2.0000 Z: 31.00000 LOCAL ROT MATRIX: 0.0000000-0.7071068-0.7071068 1.0000000 0.0000000 0.0000000 0.0000000-0.7071068 0.7071068 ATOM -7: X=0.11071984 Y=0.11071984 Z=0.11071984 MULT= 4 ISPLIT= 4 -7: X=0.88928016 Y=0.88928016 Z=0.11071984 -7: X=0.88928016 Y=0.11071984 Z=0.88928016 -7: X=0.11071984 Y=0.88928016 Z=0.88928016 As1 NPT= 781 R0=0.00005000 RMT= 2.0000 Z: 33.00000 LOCAL ROT MATRIX: 0.4082483-0.7071068 0.5773503 0.4082483 0.7071068 0.5773503 -0.8164966 0.0000000 0.5773503 ATOM -8: X=0.12494606 Y=0.12494606 Z=0.62513581 MULT=12 ISPLIT= 8 -8: X=0.87505394 Y=0.87505394 Z=0.62513581 -8: X=0.87505394 Y=0.12494606 Z=0.37486419 -8: X=0.12494606 Y=0.87505394 Z=0.37486419 -8: X=0.62513581 Y=0.12494606 Z=0.12494606 -8: X=0.62513581 Y=0.87505394 Z=0.87505394 -8: X=0.37486419 Y=0.87505394 Z=0.12494606 -8: X=0.37486419 Y=0.12494606 Z=0.87505394 -8: X=0.12494606 Y=0.62513581 Z=0.12494606 -8: X=0.87505394 Y=0.62513581 Z=0.87505394 -8: X=0.12494606 Y=0.37486419 Z=0.87505394 -8: X=0.87505394 Y=0.37486419 Z=0.12494606 As2 NPT= 781 R0=0.00005000 RMT= 2.0000 Z: 33.00000 LOCAL ROT MATRIX: 0.0000000-0.7071068-0.7071068 0.0000000-0.7071068 0.7071068 -1.0000000 0.0000000 0.0000000 ATOM -9: X=0.37283866 Y=0.12444999 Z=0.37283866 MULT=12 ISPLIT= 8 -9: X=0.62716134 Y=0.87555001 Z=0.37283866 -9: X=0.62716134 Y=0.12444999 Z=0.62716134 -9: X=0.37283866 Y=0.87555001 Z=0.62716134 -9: X=0.37283866 Y=0.37283866 Z=0.12444999 -9: X=0.37283866 Y=0.62716134 Z=0.87555001 -9: X=0.62716134 Y=0.62716134 Z=0.12444999 -9: X=0.62716134 Y=0.37283866 Z=0.87555001 -9: X=0.12444999 Y=0.37283866 Z=0.37283866 -9: X=0.87555001 Y=0.37283866 Z=0.62716134 -9: X=0.12444999 Y=0.62716134 Z=0.62716134 -9: X=0.87555001 Y=0.62716134 Z=0.37283866 As3 NPT= 781 R0=0.00005000 RMT= 2.0000 Z: 33.00000 LOCAL ROT MATRIX: 0.0000000-0.7071068-0.7071068 1.0000000 0.0000000 0.0000000 0.0000000-0.7071068 0.7071068 ATOM -10: X=0.62498650 Y=0.62498650 Z=0.62498650 MULT= 4 ISPLIT= 4 -10: X=0.37501350 Y=0.37501350 Z=0.62498650 -10: X=0.37501350 Y=0.62498650 Z=0.37501350 -10: X=0.62498650 Y=0.37501350 Z=0.37501350 As4 NPT= 781 R0=0.00005000 RMT= 2.0000 Z: 33.00000 LOCAL ROT MATRIX: 0.4082483-0.7071068 0.5773503 0.4082483 0.7071068 0.5773503 -0.8164966 0.0000000 0.5773503 As I wrote in my previous letters, my main problem is in RMTs. The distance between N atoms in N-N interstitial pair is small - slightly larger then that in isolated N2 molecule (some about 1.4-1.5 A). So, I am forced to take for N atoms RMT(N)=1.0-1.2, while for Ga and P atoms RMT(P,Ga)=1.8-2.0. The difference between these values is extremely large that should not be the case (according to the User Guide). In my opinion the only choice is to reduce RMT(P,Ga) and to take the* *separation energy between core and valence states equal to -10Ry, though this value is much lower then recommended value -6 Ry. Are my suggestions reasonable or I am on the wrong way? Thank you once again. Kakha E.A.Moore wrote: > If you want to study a pair of interstitial N atoms, you must add two N > atoms, not replace P. Or if you are replacing P by two interstitial N atoms, > you remove one P and add two N at new positions. > Interstitial means the atoms are not on lattice sites. > If the reduced cell has 16 inequivalent atoms, it sounds as though you have > 64 not 65 atoms, so possibly you have just replaced P by N on four sites. > > Are you trying to add an interstitial N2 molecule? If not why do you need two > N atoms? > > Elaine A. Moore > > ________________________________________ > From: Kakhaber Jandieri [Kakhaber.Jandieri at physik.uni-marburg.de] > Sent: 04 July 2010 15:04 > To: A Mailing list for WIEN2k users > Subject: Re: [Wien] Interstitial N-N pair in GaP supercell > > Dear Swati, > > Thank you for advice, but I still want to clarify some questions: > > "first of all I think you can't replace one atom by a pair of atoms". > > My final goal is to obtain the relaxed atom positions in GaP supercell > where one of the P atoms is replaced by the interstitial pair of > Nitrogen-Nitrogen atoms. > To say truth, I am not sure in correctness of my approach but I did the > following: > Step1 - Using the program "supercell" I generated 2x2x2 supercell for > GaP containing 64 atoms > Step2 - I construct a new supercell with 64 inequivalent atoms using > the positions obtained in Step1 > Step3 - I split one P atom in 2 atoms > Step4 - I changed the atoms obtained in Step3 from P to N > Step5 - I ran "x sgroup". It converted my "p" supercell with 65 > inequivalent atoms into the "111_p-42m" supercell with 16 inequivalent atoms > Step6 - I ran the program "mini". > > Could you advice me the correct way for constructing the supercell with > interstitial pair of N-N atoms in GaP matrix? > > > "Set 5% less RMT for all types of atoms instead of reduction of RMT of N > only and run mini" > > In interstitial N-N pair the interatomic distance between N atoms might be > significantly smaller then the distance between Ga and P atoms. > > If instead of 2.0 I take 5% less RMT, then how cam I prevent the overlapping > of spheres between the N atoms in the interstitial pair? > > > Beforehand thankfull, > Kakha > > > > > > swati chaudhury wrote: > >> Hello, >> first of all I think you can't replace one atom by a pair of atoms. >> Set 5% less RMT for all types of atoms instead of reduction of RMT of N only >> and run mini. >> best wishes. >> swati >> >> --- On Sun, 4/7/10, Kakhaber Jandieri <Kakhaber.Jandieri at >> physik.uni-marburg.de> wrote: >> >> >> >>> From: Kakhaber Jandieri <Kakhaber.Jandieri at physik.uni-marburg.de> >>> Subject: [Wien] Interstitial N-N pair in GaP supercell >>> To: wien at zeus.theochem.tuwien.ac.at >>> Date: Sunday, 4 July, 2010, 5:17 PM >>> In addition to my previous letter. >>> >>> I thought that may be the problem is in very large >>> difference between the RMT(Ga,P)=2.0 and RMT (N)=1.0, but I >>> cannot increase the RMT(N) because >>> of overlapping spheres and, on the other hand, I cannot >>> decrease the RMT(Ga,P) because of charge leakage. >>> >>> >>> Could somebody advice the solution of this problem? >>> >>> I will be extremely thankful for any suggestion. >>> >>> _______________________________________________ >>> Wien mailing list >>> Wien at zeus.theochem.tuwien.ac.at >>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien >>> >>> >>> >> _______________________________________________ >> Wien mailing list >> Wien at zeus.theochem.tuwien.ac.at >> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien >> >> >> > > _______________________________________________ > Wien mailing list > Wien at zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > >