Vacuum size effect on total energy

[satish2414]

I am working on ice bilayer adsorption on Pt(111) surface. I have performed two calculations with a vacuum spacing (top of ice bilayer - bottom of Pt layer) of around i) 4.7 and ii) 12.83 Angstroms. I get a difference [ ii) case - i) case] of total energy (energy without entropy after geometry optimization) between these two cases around +0.85 eV. The structure is similar in two cases. Is this large deviation arising as a result of more planewaves considered(

The increase of the box volume leads to the increase of the number of plane waves.
Although the molecules remains the same, the size of the basis set increases.
Therefore the calculated energies (both E0 and EXX) differ.
The best way how to deal with it is to use the same box for all calculations.

) ? If so, then why does increase in vacuum converges with the total energy (in the usual vacuum tests for slab calculations) as, when above quoted is true, increase in vacuum also implies increase in more planewaves and hence this changes the total energy. Or is the quoted response only applicable for Hartree-Fock calculation?

To get around this issue, I just need to be consistent with the vacuum thickness throughout the set of calculations and the differences in total energy between two equivalent vacuum sized calculations will be meaningful/correct. Is that right?

The INCAR and POSCAR are given below:

ISTART = 0
ISMEAR = 1
SIGMA = 0.15
IBRION = 2
NSW = 500
PREC = normal
ENCUT = 450 eV
ISIF = 2
EDIFF = 1E-5
EDIFFG = -0.05

Sample POSCAR_case1:
Pt O H
1.0000000000000000
8.4428549673673778 0.0000000000000000 0.0000000000000000
4.2214274836836889 7.3117268822077861 0.0000000000000000
0.0000000000000000 0.0000000000000000 26.8935622141241346
36 24 47
Selective dynamics
Cartesian
4.2506490155480190 7.2645875006963223 10.0849599245745569 T T T
7.0634777458775506 7.2741487867314714 9.9530833421215217 T T T
9.8710622174692872 7.2735295046909236 10.0490046591876716 T T T
1.4425676648391821 2.4009508777332194 10.0592223594171042 T T T
4.2488491546914338 2.3972905437959295 10.0274752313006132 T T T
7.0724743724526640 2.3878063806631937 9.8821831646393115 T T T
2.8435374920171648 4.8388064334379735 9.9617873203333538 T T T
5.6554235143920506 4.8308652409429413 10.0384520193195765 T T T
8.4686236839310887 4.8348817292669066 10.0595691733613091 T T T
1.4308705823467207 0.7938306929899854 12.3388058629376065 T T T
4.2185987462720229 0.7901699493831559 12.3190848926694123 T T T
7.0448777838534493 0.8099650458637319 12.3210791823337296 T T T
2.8370317032146302 3.2509709108454441 12.3174852985515511 T T T
5.6675476239816618 3.2137526842125479 12.2896138642527433 T T T
8.4441243398369839 3.2245310564275300 12.3210517106132169 T T T
4.2301167561841169 5.6530007286516648 12.3331828754162434 T T T
7.0474757828368855 5.6873176284340250 12.3212691477567553 T T T
9.8738353150548015 5.6638047017338256 12.3304101561704229 T T T
8.4428549673673476 1.6248281960461688 14.5957081427494622 F F F
2.8142849891224486 1.6248281960461688 14.5957081427494622 F F F
5.6285699782449283 1.6248281960461688 14.5957081427494622 F F F
9.8499974619285879 4.0620704901154481 14.5957081427494622 F F F
4.2214274836836889 4.0620704901154481 14.5957081427494622 F F F
7.0357124728061677 4.0620704901154481 14.5957081427494622 F F F
11.2571399564897963 6.4993127841846761 14.5957081427494622 F F F
5.6285699782448981 6.4993127841846761 14.5957081427494622 F F F
8.4428549673673778 6.4993127841846761 14.5957081427494622 F F F
0.0000000000000000 0.0000000000000000 16.8935622141240600 F F F
2.8142849891224793 0.0000000000000000 16.8935622141240600 F F F
5.6285699782448981 0.0000000000000000 16.8935622141240600 F F F
1.4071424945612396 2.4372422940692795 16.8935622141240600 F F F
4.2214274836837191 2.4372422940692795 16.8935622141240600 F F F
7.0357124728061375 2.4372422940692795 16.8935622141240600 F F F
2.8142849891224491 4.8744845881385066 16.8935622141240600 F F F
5.6285699782449283 4.8744845881385066 16.8935622141240600 F F F
8.4428549673673476 4.8744845881385066 16.8935622141240600 F F F
7.2467174479408962 2.2991843608758793 22.6821463900140685 T T T
8.6109199392189595 4.6689184078347417 23.3845482565758047 T T T
7.2360427213892313 7.1349304336644224 22.6651240010582953 T T T
12.7857686192163467 7.1071932996578937 23.4474169439568954 T T T
11.4562536421436487 4.7413028823913557 22.6617264196806154 T T T
4.3660031995174098 2.2119753633894041 23.3013116681460204 T T T
2.7992912828811889 4.9705015637154562 7.5888962598229028 T T T
3.1237285367931076 2.3241577160539770 6.4564555711469529 T T T
7.2832304822180696 2.2627960146421158 7.8332670881967816 T T T
8.6123732174126690 5.0735107181660739 6.7465026227063234 T T T
2.6697643613593418 -0.0423030126623890 7.5860033912582043 T T T
8.3688521299443188 0.0167481569971782 6.8658022626880832 T T T
7.0469921728376841 2.4736848554851125 3.0665718815683127 T T T
8.4111946641157544 4.8434189024439442 3.7689737481300405 T T T
7.0363174462860201 7.3094309282736250 3.0495494926125373 T T T
12.5860433441131399 7.2816937942670990 3.8318424355111294 T T T
11.2565283670404472 4.9158033770005609 3.0461519112348574 T T T
4.1662779244142296 2.3864758579986405 3.6857371597002553 T T T
2.8606993877689471 4.8894878309697614 0.0687719072173849 T T T
4.2066563665713463 2.5355948139760733 26.2708089652572667 T T T
7.0804325116050952 2.4411589708707648 0.0586949746589628 T T T
8.4288918726911248 4.9714510096979083 26.2558551350160094 T T T
7.0748887019637952 7.3049139029595569 0.0647028695136645 T T T
8.4284105423921503 0.1054792327681812 26.2531767415844897 T T T
10.2796211040277559 5.0840953143935641 7.3307812970550401 T T T
11.7054106344639006 5.8329310701544772 7.3719107775970940 T T T
3.7096749183826865 2.3740533685557281 5.6727808907998583 T T T
3.1922774545411152 3.1890670066123135 6.9256032788769017 T T T
7.7389843205376092 3.0959240379586204 7.5805628259297437 T T T
8.4919448116322052 4.9846719323893138 5.7742940890910903 T T T
8.0296764352664844 5.8209452902358967 7.0337295008493532 T T T
1.6893378507693486 -0.0946374999367867 7.3960921444874588 T T T
2.9335056670358797 0.8750414635665645 7.2509053185596217 T T T
8.3353294013685151 0.0817761667273724 5.8856212113472495 T T T
7.9838529962482463 0.8903717171782315 7.2316063599784597 T T T
7.0980144511454366 2.4849213474127674 2.0860525726364587 T T T
7.5210224638469541 3.3011426883242025 3.3590212109467781 T T T
9.3725052532775877 4.9183233021850263 3.5445561524433642 T T T
7.9917326637913337 5.7121678435598904 3.5428866090034377 T T T
2.8432276386100543 0.0084942069307496 2.0666746984873603 T T T
3.2857015875591586 0.8347557269973656 3.3226030099024286 T T T
0.8821526856143771 0.0376037637993325 3.6115580565062291 T T T
7.9582239158275900 0.8440256751031243 3.6065597092172901 T T T
2.8565161137663648 4.9511125701755336 2.0647519608781209 T T T
11.7221122942305591 5.7415971013856719 3.3575371416827524 T T T
5.1361675691275259 2.4798079827375914 3.5216319980792563 T T T
3.7516125736286448 3.2654159298181327 3.5038329355508178 T T T
10.3434212045458374 4.9602936532677759 26.7385509625638740 T T T
3.2724278302814405 5.7573134676946447 26.7278487425415925 T T T
4.1817590304485135 2.5694394118674846 25.2975360548042651 T T T
3.7307818446799668 3.3676712248098633 26.5586786044322452 T T T
6.1187491218830408 2.5167492426977427 26.7367893925719429 T T T
7.4923459585501551 3.3107356229444673 26.7259089106161056 T T T
8.4155353866239651 5.0093254861740784 25.2824379132309538 T T T
7.9453760644472471 5.8006339204193456 26.5417538614218600 T T T
1.8929435863769473 0.0748587416431172 26.7403081517358245 T T T
3.2687956375656237 0.8641815765092430 26.7447696580615606 T T T
8.4156851462649254 0.1366531141219354 25.2796028181091117 T T T
7.9473264153052714 0.9382081859570488 26.5344651926036583 T T T
7.2977397262486479 2.3104208528035342 21.7016270810822007 T T T
7.7207477389501680 3.1266421937149893 22.9745957193925392 T T T
9.5722305283807927 4.7438228075758211 23.1601306608891271 T T T
8.1914579388945423 5.5376673489506860 23.1584611174491997 T T T
3.0429529137132243 -0.1660062876785105 21.6822492069331041 T T T
3.4854268626623304 0.6602552323881125 22.9381775183481906 T T T
1.0818779607175477 -0.1368967308099273 23.2271325649519937 T T T
8.1579491909308004 0.6695251804938706 23.2221342176630543 T T T
3.0562413888695343 4.7766120755663284 21.6803264693238624 T T T
11.9218375693337659 5.5670966067764667 22.9731116501285122 T T T
5.3358928442307176 2.3053074881283591 23.1372065065250183 T T T
3.9513378487318214 3.0909154352089181 23.1194074439965824 T T T

POSCAR_case2:
Pt O H
1.0000000000000000
8.4428549673673778 0.0000000000000000 0.0000000000000000
4.2214274836836889 7.3117268822077861 0.0000000000000000
0.0000000000000000 0.0000000000000000 35.0000000000000000
36 24 47
Selective dynamics
Cartesian
4.3843403293471770 7.4978968130100956 22.1661392733069604 T T T
7.1923467952746734 7.5103932690357720 22.0196507633011223 T T T
10.0045581738369069 7.5085438109656533 22.1331995047192507 T T T
1.5779494085481942 2.6381109447831137 22.1404368067098360 T T T
4.3825130819238813 2.6346867748378711 22.1068605538601872 T T T
7.2027152588270411 2.6306043179467991 21.9785372520705877 T T T
2.9716114340295743 5.0763724793576266 22.0230696067343885 T T T
5.7881526531251062 5.0667281644672784 22.1189238366304295 T T T
8.6020044590372589 5.0713625612420117 22.1393314470205951 T T T
1.5704580600881988 1.0222441036292609 24.4194674986891727 T T T
4.3561725240010238 1.0182325249141284 24.3973504802006644 T T T
7.1851509432808616 1.0381365638303235 24.4036018130278052 T T T
2.9777987051587220 3.4797957600622293 24.3966507194465692 T T T
5.8072121948598259 3.4419371208948473 24.3722538265792394 T T T
8.5867262819730943 3.4549645092852277 24.4055933439636945 T T T
4.3688833790479631 5.8807119448487981 24.4123944157608079 T T T
7.1866842021241268 5.9147779215137284 24.4019756332416264 T T T
10.0150096905882791 5.8927604167112246 24.4123515793883641 T T T
8.5870275419136348 1.8476825868895472 26.6807423668230683 F F F
2.9584575636687358 1.8476825868895472 26.6807423668230683 F F F
5.7727425527912155 1.8476825868895472 26.6807423668230683 F F F
9.9941700364748751 4.2849248809588261 26.6807423668230683 F F F
4.3656000582299761 4.2849248809588261 26.6807423668230683 F F F
7.1798850473524549 4.2849248809588261 26.6807423668230683 F F F
11.4013125310360834 6.7221671750280549 26.6807423668230683 F F F
5.7727425527911853 6.7221671750280549 26.6807423668230683 F F F
8.5870275419136650 6.7221671750280549 26.6807423668230683 F F F
0.1441725745462872 0.2228543908433784 28.9785964381976626 F F F
2.9584575636687664 0.2228543908433784 28.9785964381976626 F F F
5.7727425527911853 0.2228543908433784 28.9785964381976626 F F F
1.5513150691075268 2.6600966849126579 28.9785964381976626 F F F
4.3656000582300063 2.6600966849126579 28.9785964381976626 F F F
7.1798850473524247 2.6600966849126579 28.9785964381976626 F F F
2.9584575636687362 5.0973389789818846 28.9785964381976626 F F F
5.7727425527912155 5.0973389789818846 28.9785964381976626 F F F
8.5870275419136348 5.0973389789818846 28.9785964381976626 F F F
7.4009793282270344 2.5302976370426520 7.8449233402868863 T T T
8.7343761675015017 4.9275143481598747 8.6040921462117410 T T T
7.3802541193079136 7.3883816351898535 7.8341370969645645 T T T
4.4949749241227126 7.3725761321489909 8.6242214096295093 T T T
3.1612340212497947 4.9766155957956641 7.8273808598600780 T T T
4.4987595985457247 2.4837315413080283 8.5822259014010349 T T T
4.3720878894108646 2.7169814348552608 11.4669389858627646 T T T
8.5983048247039413 5.1503557180418618 11.4711384209764482 T T T
8.5939023312695166 0.2783870824457814 11.4892468342436658 T T T
11.3473427816748913 5.2120125657292906 19.6959829276599478 T T T
3.3394653100519709 2.5197669052829594 18.5579034602365311 T T T
7.4321210936797826 2.4855991643584190 19.9428631319086236 T T T
8.7667499142873044 5.2817085031952846 18.8139024004490309 T T T
7.0256468002354389 7.5100320760849666 19.6958362947502579 T T T
8.5163351782393146 0.2029049189536975 18.9240747892338064 T T T
7.1935919959323069 2.6774027966004965 15.1358297636997960 T T T
8.5780049346105880 5.0992595162100365 15.9447928071320781 T T T
2.9550289677704074 0.2131699925739306 15.1171578217542688 T T T
8.5332172620600275 0.2276330847389949 15.9974689694170564 T T T
11.4005447182618180 5.1290043819783211 15.1099063572493186 T T T
4.3067089100752893 2.6403010874131154 15.8571104165765888 T T T
2.9831869719405639 5.1463441891839139 12.2129642641293970 T T T
7.2068086237644771 2.7010803132768353 12.2139857138351680 T T T
2.9728924006676083 0.2519094050932048 12.2077449172539474 T T T
10.3854840361832359 5.3155129462896884 19.4084392041870899 T T T
11.8264022010487064 6.0561215124967074 19.4365029954735746 T T T
3.8093427487548639 2.5884446125613367 17.6936597299746836 T T T
3.3400787334624606 3.4115459859671673 18.9719558276398246 T T T
7.8611414956431265 3.3264681595258092 19.6656872439678736 T T T
8.6815850408103525 5.2173338242707743 17.8285682893549691 T T T
8.1824906320636739 6.0265912290996031 19.0945689514222039 T T T
6.0478448069918063 7.4561365041523544 19.4810841002483528 T T T
3.0856738333291780 1.1073050018093507 19.3367764512078040 T T T
8.5014507757251963 0.2677260948317337 17.9351340952127458 T T T
8.1199066172889243 1.0657884294509810 19.2801016293787768 T T T
7.2207415720475598 2.7088044299484695 14.1483034656850286 T T T
7.6641553487863057 3.4998669943517795 15.4349418291707394 T T T
9.5208304562459354 5.1468292798170552 15.6429195319591550 T T T
8.1416740815363937 5.9398797218769861 15.6477897785353051 T T T
2.9675720232785765 0.2315925793767311 14.1287756788930139 T T T
3.4238572521952872 1.0467596009408275 15.3895584754572674 T T T
1.0375828776198111 0.2708209236711419 15.7150767132194211 T T T
8.1143338260591680 1.0767821691096757 15.7001650283680512 T T T
11.4311980941615499 5.1710081770856071 14.1218958274120965 T T T
11.8635377362235896 5.9507095127061742 15.4234848952003389 T T T
5.2749478464040740 2.6967407789293971 15.6623895488366962 T T T
3.9060218676759964 3.5034153193287421 15.5803160525629671 T T T
10.4688308803913177 5.2103786145441173 11.9633450506968693 T T T
11.8471441212938888 6.0091070545962886 11.9623805695161138 T T T
4.3823540641124312 2.6850314454800572 10.4789913813648532 T T T
3.8920161772592552 3.5525393228404316 11.7099801062812041 T T T
6.2494836192576200 2.7657758430082251 11.9660181334041269 T T T
7.6275476575573817 3.5624675165402593 11.9593133859766354 T T T
8.6171153450204674 5.1192341659927187 10.4830569093606840 T T T
8.1123925467900477 5.9842508895914719 11.7107163903588862 T T T
2.0138918609810830 0.3216836845894399 11.9648668443385446 T T T
3.3939746418759222 1.1150321887076540 11.9625330414611284 T T T
0.1638146486086126 0.2483048683121054 10.5012012267852874 T T T
8.1143919467960597 1.1158278984834333 11.7316522471596159 T T T
7.4142992827320606 2.5624991750499446 6.8694967359993413 T T T
7.8724554219696916 3.3637781919479792 8.1264667984773560 T T T
9.6857956913074048 4.9702122817553889 8.3372296930248169 T T T
8.3171288639003009 5.7697550124526398 8.2892119822385553 T T T
7.3697734267705250 7.4141052416738091 6.8582351152297498 T T T
3.6354467483205339 0.9119769982801927 8.1006614043837324 T T T
5.4465806498629208 7.4084253495481995 8.3593065826058677 T T T
8.3069960652160741 0.9076746652373511 8.3098367726358084 T T T
3.1644349586504124 5.0280879655698172 6.8525254434629943 T T T
3.6312728712558817 5.8065632897214687 8.1207379697226258 T T T
5.4540465382010854 2.5274614206106203 8.3320758008752343 T T T
4.0878966066611531 3.3286072061442460 8.2683984407103068 T T T

POTCAR used are GGA_PBE

[support_vasp]

Hi,

We're sorry that we didn’t answer your question. This does not live up to the quality of support that we aim to provide. The team has since expanded. If we can still help with your problem, please ask again in a new post, linking to this one, and we will answer as quickly as possible.

Best wishes,

VASP