<div>Hi all,<br></div><div>I'm doing a cell optimization for gama-amino butyric acid (gaba). I got the crystal structure from the literature. The cell volume starts out at 554 A^3 and after nine cell optimization steps the cell volume is already up to 671 A^3 with no sign of stopping (the pressure deviation is 10497 bar). I'm a little concerned why the cell is growing this much. My input file is reproduced below</div>
<div><br></div><div>PRINT_LEVEL MEDIUM<br> PROJECT_NAME gaba-small<br> RUN_TYPE CELL_OPT<br> &END GLOBAL<br> &MOTION<br> &GEO_OPT<br> TYPE MINIMIZATION<br> OPTIMIZER CG<br> STEP_START_VAL 37<br>
&END GEO_OPT<br> &CELL_OPT<br> OPTIMIZER CG<br> STEP_START_VAL 1<br> &CG<br> &LINE_SEARCH<br> TYPE 2PNT<br> &END LINE_SEARCH<br> &END CG<br>
&END CELL_OPT<br> &END MOTION<br> &FORCE_EVAL<br> METHOD QS<br> STRESS_TENSOR ANALYTICAL<br> &DFT<br> WFN_RESTART_FILE_NAME wfn.wfn<br> &SCF<br> MAX_SCF 50<br> EPS_SCF 1.0000000000000001E-05<br>
SCF_GUESS RESTART<br> &END SCF<br> &XC<br> DENSITY_CUTOFF 1.0000000000000000E-10<br> GRADIENT_CUTOFF 1.0000000000000000E-10<br> TAU_CUTOFF 1.0000000000000000E-10<br> &XC_FUNCTIONAL NO_SHORTCUT<br>
&BECKE88 T<br> &END BECKE88<br> &LYP T<br> &END LYP<br> &END XC_FUNCTIONAL<br> &END XC<br> &POISSON<br> PERIODIC XYZ<br> &END POISSON<br>
&END DFT<br> &SUBSYS<br> &CELL<br> A 8.2866587835479173E+00 0.0000000000000000E+00 0.0000000000000000E+00<br> B -9.7070785062204883E-04 1.0080263794733940E+01 0.0000000000000000E+00<br>
C -2.5160696675381669E+00 -1.2862373202136999E-03 6.8212016504287982E+00<br> PERIODIC XYZ<br> MULTIPLE_UNIT_CELL 1 1 1<br> &END CELL<br> &COORD<br>
N 1.4721481908331100E+00 -1.1634588936294963E+00 -2.2675100672694453E+00<br>N -2.4708079956705889E-01 3.7971636609452739E+00 -1.1611307656596657E+00<br>N -1.4721486881004553E+00 1.1634585045245331E+00 2.2675104019888610E+00<br>
N 2.4707974025851215E-01 -3.7971670478992561E+00 1.1611554350020716E+00<br>C 1.4876190282605533E+00 -1.4348748039880759E+00 -7.8111657780957489E-01<br>C -2.2364192566865654E-01 3.5560260999327777E+00 -2.6619278087539708E+00<br>
C -1.4876194321205625E+00 1.4348745418758384E+00 7.8111706151487725E-01<br>C 2.2363627466190811E-01 -3.5560562920717329E+00 2.6619703821907787E+00<br>C 2.5617318805222045E+00 -6.1323050387776734E-01 -6.6024700466200251E-02<br>
C -1.3080750941208925E+00 4.3561575629327951E+00 -3.3836091406584416E+00<br>C -2.5617319544331290E+00 6.1323011924199688E-01 6.6025237414786206E-02<br>C 1.3080813621862344E+00 -4.3561724648519906E+00 3.3836278908641213E+00<br>
C 2.7019043314418840E+00 -1.0168924319934967E+00 1.4185619484961929E+00<br>C -3.9715605873469570E+00 3.9504573958045337E+00 1.9531287079560016E+00<br>C -2.7019051495549609E+00 1.0168919229260287E+00 -1.4185617679792353E+00<br>
C 3.9715667922202336E+00 -3.9504623778000454E+00 -1.9531182398844402E+00<br>C 1.4769696946252282E+00 -7.3413017863860630E-01 2.2958463798216395E+00<br>C -2.7743356360414402E+00 4.2807814635492134E+00 1.0461227919648513E+00<br>
C -1.4769696139923858E+00 7.3412748030202468E-01 -2.2958437828786828E+00<br>C 2.7743355232432942E+00 -4.2807839037527042E+00 -1.0461192396614527E+00<br>O 3.4238557050122026E-01 -5.3569625638592200E-01 1.7020741953757061E+00<br>
O -1.6578207341626139E+00 4.6034323029308633E+00 1.6077489644326575E+00<br>O -3.4238875773217170E-01 5.3569422708507652E-01 -1.7020736015174045E+00<br>O 1.6578209857903352E+00 -4.6034327041643017E+00 -1.6077454955123600E+00<br>
O 1.5828730162206897E+00 -8.0625559165015703E-01 3.5704742126926159E+00<br>O -2.8970704797815987E+00 4.1350059472232168E+00 -2.2305304938896439E-01<br>O -1.5828738433348271E+00 8.0625505521356922E-01 -3.5704756104358797E+00<br>
O 2.8970696406711727E+00 -4.1350062317887648E+00 2.2305718316088133E-01<br>H 2.4515139703564732E+00 -9.6026788489116932E-01 -2.6473470538201447E+00<br>H -1.2333850576003118E+00 4.0188982442868788E+00 -8.0460004075783864E-01<br>
H -2.4515140856945967E+00 9.6026800144648095E-01 2.6473472257007562E+00<br>H 1.2333858667245912E+00 -4.0188980493498185E+00 8.0461297860456149E-01<br>H 7.7793136540798380E-01 -3.4019984744904525E-01 -2.3536676930347653E+00<br>
H 4.6578611745621584E-01 4.5897601242755748E+00 -1.0174388813700546E+00<br>H -7.7793221596870055E-01 3.4020018234964966E-01 2.3536685088263503E+00<br>H -4.6578350917240030E-01 -4.5897583696611850E+00 1.0174456521067965E+00<br>
H 1.0896708400173831E+00 -1.9754049558429432E+00 -2.7768379531367242E+00<br>H 8.9296891670139197E-02 2.9553511171789477E+00 -6.6544981207939691E-01<br>H -1.0896714347479259E+00 1.9754057056439036E+00 2.7768384620958781E+00<br>
H -8.9293866323773299E-02 -2.9553500367411312E+00 6.6547685435642490E-01<br>H 4.8823594539633747E-01 -1.1717387869088651E+00 -4.0953253842159465E-01<br>H 7.7966881703478941E-01 3.8491388047771005E+00 -3.0035061725928203E+00<br>
H -4.8823639545227193E-01 1.1717384352915357E+00 4.0953280858753255E-01<br>H -7.7967656209031810E-01 -3.8491603040428917E+00 3.0035292284906667E+00<br>H 1.6854264653674020E+00 -2.4958538768170531E+00 -6.4377759424229042E-01<br>
H -3.8960039471094027E-01 2.4913302655020666E+00 -2.8129329355293753E+00<br>H -1.6854272652626461E+00 2.4958534301081570E+00 6.4377790183385852E-01<br>H 3.8959794383262908E-01 -2.4913527765554133E+00 2.8129598679937611E+00<br>
H 2.3458157653333980E+00 4.7173013650773338E-01 -1.5832911946999634E-01<br>H -1.1015546858068639E+00 -4.6376673788781151E+00 -3.2973918925961061E+00<br>H -2.3458159941345160E+00 -4.7173035645041950E-01 1.5832924734061471E-01<br>
H 1.1015643847834848E+00 4.6376523797710947E+00 3.2974032356113332E+00<br>H 3.5281665701542608E+00 -8.0130985528225562E-01 -5.7477508347393258E-01<br>H -2.2736035795373524E+00 4.1650929902843279E+00 -2.8709010371643857E+00<br>
H -3.5281669248180201E+00 8.0130969420319398E-01 5.7477536048121558E-01<br>H 2.2736049169380999E+00 -4.1650941656349127E+00 2.8709049698971527E+00<br>H 3.5526308319882705E+00 -5.0688587563135745E-01 1.8902006515008498E+00<br>
H 3.4400206495260206E+00 4.4440495831290772E+00 1.5051157506376562E+00<br>H -3.5526318417082932E+00 5.0688579215902063E-01 -1.8902004106852883E+00<br>H -3.4400165105337850E+00 -4.4440496259831264E+00 -1.5051042927303591E+00<br>
H 2.9123764367143075E+00 -2.1049077007844086E+00 1.4813794716289823E+00<br>H 4.1313768343804993E+00 2.8580112466180556E+00 1.8855606418076587E+00<br>H -2.9123762860598443E+00 2.1049075315475609E+00 -1.4813794907991644E+00<br>
H -4.1313764950699650E+00 -2.8580139615363040E+00 -1.8855593678632319E+00<br> &END COORD<br> &KIND H<br> BASIS_SET DZVP-GTH<br> POTENTIAL GTH-BLYP-q1<br> &BASIS<br>2<br>1 0 0 4 2<br>
0.8374435000900000E+01 -0.2833804610000000E-01 0.0000000000000000E+00<br>0.1805868146000000E+01 -0.1333810052000000E+00 0.0000000000000000E+00<br>0.4852528328000000E+00 -0.3995676063000000E+00 0.0000000000000000E+00<br>
0.1658236932000000E+00 -0.5531027541000000E+00 0.1000000000000000E+01<br>2 1 1 1 1<br>0.7270000000000000E+00 0.1000000000000000E+01<br> &END BASIS<br> &POTENTIAL<br>1<br>0.2000000000000000E+00 2 -0.4195961470000000E+01 0.7304982100000000E+00<br>
0<br> &END POTENTIAL<br> &END KIND<br> &KIND C<br> BASIS_SET DZVP-GTH<br> POTENTIAL GTH-BLYP-q4<br> &BASIS<br>2<br>2 0 1 4 2 2<br>0.4336237643600000E+01 0.1490797872000000E+00 0.0000000000000000E+00 -0.8781236190000000E-01 0.0000000000000000E+00<br>
0.1288183851300000E+01 -0.2926400310000000E-01 0.0000000000000000E+00 -0.2775560300000000E+00 0.0000000000000000E+00<br>0.4037767149000000E+00 -0.6882040510000000E+00 0.0000000000000000E+00 -0.4712295093000000E+00 0.0000000000000000E+00<br>
0.1187877657000000E+00 -0.3964426906000000E+00 0.1000000000000000E+01 -0.4058039291000000E+00 0.1000000000000000E+01<br>3 2 2 1 1<br>0.5500000000000000E+00 0.1000000000000000E+01<br> &END BASIS<br> &POTENTIAL<br>
2 2<br>0.3380660900000000E+00 2 -0.9136268710000000E+01 0.1429259560000000E+01<br>2<br>0.3023222300000000E+00 1 0.9665512280000000E+01<br>0.2863791200000000E+00 0<br> &END POTENTIAL<br> &END KIND<br> &KIND O<br>
BASIS_SET DZVP-GTH<br> POTENTIAL GTH-BLYP-q6<br> &BASIS<br>2<br>2 0 1 4 2 2<br>0.8304385549199999E+01 0.1510165999000000E+00 0.0000000000000000E+00 -0.9956792730000000E-01 0.0000000000000000E+00<br>
0.2457948419100000E+01 -0.3931953640000000E-01 0.0000000000000000E+00 -0.3011422449000000E+00 0.0000000000000000E+00<br>0.7597373434000000E+00 -0.6971724029000000E+00 0.0000000000000000E+00 -0.4750857083000000E+00 0.0000000000000000E+00<br>
0.2136388632000000E+00 -0.3841133622000000E+00 0.1000000000000000E+01 -0.3798777957000000E+00 0.1000000000000000E+01<br>3 2 2 1 1<br>0.1185000000000000E+01 0.1000000000000000E+01<br> &END BASIS<br> &POTENTIAL<br>
2 4<br>0.2434202600000000E+00 2 -0.1699189235000000E+02 0.2566142060000000E+01<br>2<br>0.2208314000000000E+00 1 0.1838885102000000E+02<br>0.2172007000000000E+00 0<br> &END POTENTIAL<br> &END KIND<br> &KIND N<br>
BASIS_SET DZVP-GTH<br> POTENTIAL GTH-BLYP-q5<br> &BASIS<br>2<br>2 0 1 4 2 2<br>0.6152690341300000E+01 0.1506300537000000E+00 0.0000000000000000E+00 -0.9506034760000000E-01 0.0000000000000000E+00<br>
0.1823633228000000E+01 -0.3601007340000000E-01 0.0000000000000000E+00 -0.2918864295000000E+00 0.0000000000000000E+00<br>0.5676628870000000E+00 -0.6942023212000000E+00 0.0000000000000000E+00 -0.4739050050000000E+00 0.0000000000000000E+00<br>
0.1628222852000000E+00 -0.3878929987000000E+00 0.1000000000000000E+01 -0.3893418670000000E+00 0.1000000000000000E+01<br>3 2 2 1 1<br>0.8169999999999999E+00 0.1000000000000000E+01<br> &END BASIS<br> &POTENTIAL<br>
2 3<br>0.2828709400000000E+00 2 -0.1273646720000000E+02 0.1951079260000000E+01<br>2<br>0.2552344900000000E+00 1 0.1367893172000000E+02<br>0.2431325300000000E+00 0<br> &END POTENTIAL<br> &END KIND<br> &TOPOLOGY<br>
NUMBER_OF_ATOMS 64<br> MULTIPLE_UNIT_CELL 1 1 1<br> &END TOPOLOGY<br> &END SUBSYS<br> &END FORCE_EVAL<br></div>