#ifndef GBNECK_H
#define GBNECK_H

/* GBNECKCUT: 2.8 (diameter of water) is the 'correct' value, but larger values
 * give smaller discontinuities at the cut.
 */
static const REAL_T GBNECKCUT = 6.8;

/* Lookup tables for position (atom separation, r) and the value of the max neck
 * function for given atomic radii ri and rj. Values of neck maximum are already
 * divided by 4*pi to save time. Values are given for each 0.05 Angstrom between
 * 1.0 and 2.0, inclusive, so map to index with int((r-1.0)*20). Values were
 * numerically determined in Mathematica; note C row-major array storage, so the
 * data is transposed with respect to the version in the Fortran (sander/pmemd)
 * code
 */
static const REAL_T neckMaxPos[21][21] = {
  {2.26684999, 2.31190991, 2.35758996, 2.40380001, 2.45044994, 2.49749994, 2.54488993,
   2.59259009, 2.64053988, 2.68873000, 2.73712993, 2.78572011, 2.83446002, 2.88334990,
   2.93233991, 2.98150992, 3.03074002, 3.08008003, 3.12948990, 3.17898989, 3.22854996},
  {2.32547998, 2.37017012, 2.41548991, 2.46138000, 2.50773001, 2.55450010, 2.60163999,
   2.64910007, 2.69684005, 2.74482012, 2.79302001, 2.84142995, 2.89000010, 2.93873000,
   2.98760009, 3.03660011, 3.08571005, 3.13491988, 3.18422008, 3.23360991, 3.28307009},
  {2.38397002, 2.42829990, 2.47328997, 2.51885009, 2.56491995, 2.61142993, 2.65829992,
   2.70552993, 2.75305009, 2.80082989, 2.84884000, 2.89706993, 2.94547009, 2.99404001,
   3.04276991, 3.09162998, 3.14060998, 3.18969989, 3.23887992, 3.28815007, 3.33751011},
  {2.44234991, 2.48632002, 2.53097010, 2.57623005, 2.62200999, 2.66825008, 2.71487999,
   2.76187992, 2.80918002, 2.85676003, 2.90458989, 2.95264006, 3.00088000, 3.04928994,
   3.09786010, 3.14658999, 3.19543004, 3.24440002, 3.29346991, 3.34263992, 3.39188004},
  {2.50057006, 2.54419994, 2.58854008, 2.63351011, 2.67899990, 2.72498989, 2.77133989,
   2.81815004, 2.86523008, 2.91262007, 2.96026993, 3.00813007, 3.05621004, 3.10447001,
   3.15290999, 3.20148993, 3.25021005, 3.29905009, 3.34800005, 3.39705992, 3.44619989},
  {2.55867004, 2.60196996, 2.64599991, 2.69067001, 2.73589993, 2.78163004, 2.82780004,
   2.87434006, 2.92122006, 2.96841002, 3.01587009, 3.06356001, 3.11146998, 3.15959001,
   3.20787001, 3.25632000, 3.30490994, 3.35363007, 3.40247011, 3.45142007, 3.50045991},
  {2.61663008, 2.65961003, 2.70333004, 2.74773002, 2.79270005, 2.83818007, 2.88411999,
   2.93043995, 2.97711992, 3.02412009, 3.07139993, 3.11892009, 3.16669011, 3.21463990,
   3.26277995, 3.31110001, 3.35956001, 3.40814996, 3.45688009, 3.50570989, 3.55466008},
  {2.67443991, 2.71710992, 2.76056004, 2.80468988, 2.84940004, 2.89463997, 2.94034004,
   2.98645997, 3.03294992, 3.07976007, 3.12685990, 3.17422009, 3.22182989, 3.26962996,
   3.31764007, 3.36580992, 3.41415000, 3.46263003, 3.51124001, 3.55996990, 3.60879993},
  {2.73212004, 2.77449012, 2.81766009, 2.86152005, 2.90598989, 2.95100999, 2.99650002,
   3.04240990, 3.08870006, 3.13532996, 3.18225002, 3.22946000, 3.27689004, 3.32455993,
   3.37242007, 3.42047000, 3.46868992, 3.51704001, 3.56554008, 3.61416006, 3.66289997},
  {2.78964996, 2.83174992, 2.87465000, 2.91826010, 2.96250010, 3.00728989, 3.05256009,
   3.09826994, 3.14437008, 3.19081998, 3.23757005, 3.28462005, 3.33190989, 3.37943006,
   3.42716002, 3.47507000, 3.52316999, 3.57140994, 3.61980009, 3.66830993, 3.71693993},
  {2.84704995, 2.88887000, 2.93151999, 2.97488999, 3.01889992, 3.06346011, 3.10853004,
   3.15404010, 3.19995999, 3.24622989, 3.29281998, 3.33971000, 3.38685012, 3.43424010,
   3.48183990, 3.52962995, 3.57758999, 3.62572002, 3.67400002, 3.72240996, 3.77095008},
  {2.90429997, 2.94585991, 2.98827004, 3.03139997, 3.07518005, 3.11953998, 3.16441989,
   3.20973992, 3.25548005, 3.30156994, 3.34801006, 3.39474010, 3.44174004, 3.48898005,
   3.53661990, 3.58411002, 3.63195992, 3.67998004, 3.72814989, 3.77644992, 3.82488990},
  {2.96141005, 3.00272989, 3.04489994, 3.08781004, 3.13138008, 3.17553997, 3.22021008,
   3.26536012, 3.31090999, 3.35684991, 3.40313005, 3.44970989, 3.49656010, 3.54365993,
   3.59100008, 3.63855004, 3.68628001, 3.73417997, 3.78224993, 3.83046007, 3.87879992},
  {3.01839995, 3.05947995, 3.10141993, 3.14409995, 3.18747997, 3.23143005, 3.27591991,
   3.32088995, 3.36627007, 3.41205001, 3.45814991, 3.50460005, 3.55132008, 3.59829998,
   3.64550996, 3.69292998, 3.74054003, 3.78834009, 3.83628988, 3.88439989, 3.93265009},
  {3.07523990, 3.11610007, 3.15781999, 3.20030999, 3.24346995, 3.28723001, 3.33154011,
   3.37632990, 3.42156005, 3.46718001, 3.51314998, 3.55943990, 3.60601997, 3.65286994,
   3.69994998, 3.74725008, 3.79475999, 3.84243989, 3.89030004, 3.93830991, 3.98645997},
  {3.13195992, 3.17260003, 3.21410990, 3.25638008, 3.29937005, 3.34294009, 3.38706994,
   3.43169999, 3.47676992, 3.52222991, 3.56804991, 3.61420989, 3.66066003, 3.70737004,
   3.75434995, 3.80152988, 3.84892988, 3.89650011, 3.94425011, 3.99216008, 4.04021978},
  {3.18853998, 3.22897005, 3.27027988, 3.31237006, 3.35514998, 3.39856005, 3.44252992,
   3.48698997, 3.53189993, 3.57720995, 3.62290001, 3.66891003, 3.71522999, 3.76183009,
   3.80867004, 3.85575008, 3.90302992, 3.95051003, 3.99815989, 4.04597998, 4.09394979},
  {3.24498010, 3.28521991, 3.32633996, 3.36824989, 3.41085005, 3.45409012, 3.49789000,
   3.54219007, 3.58695006, 3.63212991, 3.67767000, 3.72356009, 3.76975012, 3.81622005,
   3.86295009, 3.90990996, 3.95708990, 4.00446987, 4.05203009, 4.09974003, 4.14762020},
  {3.30132008, 3.34136009, 3.38229990, 3.42402005, 3.46645999, 3.50952005, 3.55315995,
   3.59731007, 3.64193010, 3.68695998, 3.73236990, 3.77814007, 3.82420993, 3.87055993,
   3.91718006, 3.96403003, 4.01110983, 4.05837011, 4.10583019, 4.15347004, 4.20126009},
  {3.35752010, 3.39738011, 3.43812990, 3.47970009, 3.52196002, 3.56487989, 3.60836005,
   3.65236998, 3.69684005, 3.74173999, 3.78700995, 3.83263993, 3.87859988, 3.92483997,
   3.97133994, 4.01808977, 4.06506014, 4.11223984, 4.15960979, 4.20714998, 4.25484991},
  {3.41359997, 3.45072007, 3.49387002, 3.53526998, 3.57737994, 3.62014008, 3.66348004,
   3.70734000, 3.75166988, 3.79643989, 3.84158993, 3.88709998, 3.93292999, 3.97904992,
   4.02545023, 4.07211018, 4.11896992, 4.16604996, 4.21332979, 4.26077986, 4.30840015}
}; // end of neckMaxPos

static const REAL_T neckMaxVal[21][21] = {
  {0.03815110, 0.03961980, 0.04104800, 0.04243650, 0.04378610, 0.04509790, 0.04637290,
   0.04761230, 0.04881710, 0.04998830, 0.05112720, 0.05223480, 0.05331230, 0.05436060,
   0.05538070, 0.05637380, 0.05734060, 0.05828220, 0.05919940, 0.06009320, 0.06096420},
  {0.03385870, 0.03518370, 0.03647380, 0.03772950, 0.03895160, 0.04014060, 0.04129760,
   0.04242330, 0.04351860, 0.04458450, 0.04562190, 0.04663150, 0.04761450, 0.04857160,
   0.04950370, 0.05041160, 0.05129630, 0.05215840, 0.05299870, 0.05381800, 0.05461690},
  {0.03017760, 0.03137670, 0.03254560, 0.03368460, 0.03479440, 0.03587530, 0.03692810,
   0.03795340, 0.03895200, 0.03992460, 0.04087200, 0.04179480, 0.04269400, 0.04357000,
   0.04442390, 0.04525620, 0.04606760, 0.04685890, 0.04763070, 0.04838360, 0.04911830},
  {0.02700300, 0.02809110, 0.02915320, 0.03018930, 0.03119980, 0.03218510, 0.03314560,
   0.03408200, 0.03499470, 0.03588440, 0.03675180, 0.03759730, 0.03842180, 0.03922570,
   0.04000970, 0.04077450, 0.04152060, 0.04224860, 0.04295900, 0.04365250, 0.04432950},
  {0.02425060, 0.02524090, 0.02620840, 0.02715330, 0.02807580, 0.02897610, 0.02985470,
   0.03071180, 0.03154810, 0.03236400, 0.03315990, 0.03393650, 0.03469420, 0.03543350,
   0.03615510, 0.03685930, 0.03754680, 0.03821800, 0.03887340, 0.03951360, 0.04013880},
  {0.02185290, 0.02275630, 0.02363990, 0.02450380, 0.02534790, 0.02617260, 0.02697800,
   0.02776450, 0.02853240, 0.02928220, 0.03001420, 0.03072900, 0.03142680, 0.03210820,
   0.03277360, 0.03342350, 0.03405830, 0.03467840, 0.03528430, 0.03587640, 0.03645500},
  {0.01975470, 0.02058080, 0.02138970, 0.02218130, 0.02295550, 0.02371250, 0.02445250,
   0.02517570, 0.02588240, 0.02657290, 0.02724750, 0.02790670, 0.02855070, 0.02918000,
   0.02979490, 0.03039580, 0.03098300, 0.03155710, 0.03211820, 0.03266690, 0.03320330},
  {0.01791090, 0.01866810, 0.01941020, 0.02013710, 0.02084870, 0.02154510, 0.02222640,
   0.02289270, 0.02354430, 0.02418150, 0.02480450, 0.02541360, 0.02600900, 0.02659130,
   0.02716050, 0.02771710, 0.02826140, 0.02879380, 0.02931440, 0.02982370, 0.03032200},
  {0.01628440, 0.01697990, 0.01766220, 0.01833100, 0.01898640, 0.01962820, 0.02025670,
   0.02087180, 0.02147380, 0.02206290, 0.02263920, 0.02320300, 0.02375470, 0.02429430,
   0.02482220, 0.02533870, 0.02584410, 0.02633860, 0.02682250, 0.02729610, 0.02775960},
  {0.01484420, 0.01548430, 0.01611290, 0.01672950, 0.01733430, 0.01792700, 0.01850780,
   0.01907670, 0.01963390, 0.02017940, 0.02071350, 0.02123630, 0.02174820, 0.02224920,
   0.02273960, 0.02321970, 0.02368960, 0.02414970, 0.02460020, 0.02504130, 0.02547320},
  {0.01356470, 0.01415500, 0.01473510, 0.01530470, 0.01586370, 0.01641210, 0.01694980,
   0.01747680, 0.01799340, 0.01849940, 0.01899520, 0.01948090, 0.01995660, 0.02042250,
   0.02087880, 0.02132570, 0.02176340, 0.02219220, 0.02261210, 0.02302360, 0.02342660},
  {0.01242430, 0.01296960, 0.01350590, 0.01403300, 0.01455070, 0.01505880, 0.01555750,
   0.01604660, 0.01652620, 0.01699640, 0.01745740, 0.01790920, 0.01835200, 0.01878590,
   0.01921110, 0.01962770, 0.02003600, 0.02043620, 0.02082830, 0.02121260, 0.02158920},
  {0.01140470, 0.01190940, 0.01240610, 0.01289460, 0.01337480, 0.01384650, 0.01430960,
   0.01476420, 0.01521030, 0.01564790, 0.01607710, 0.01649800, 0.01691080, 0.01731550,
   0.01771220, 0.01810130, 0.01848260, 0.01885660, 0.01922320, 0.01958260, 0.01993510},
  {0.01049060, 0.01095840, 0.01141920, 0.01187270, 0.01231880, 0.01275730, 0.01318810,
   0.01361120, 0.01402670, 0.01443450, 0.01483480, 0.01522750, 0.01561280, 0.01599080,
   0.01636150, 0.01672520, 0.01708200, 0.01743190, 0.01777510, 0.01811180, 0.01844200},
  {0.00966876, 0.01010310, 0.01053120, 0.01095290, 0.01136790, 0.01177610, 0.01217750,
   0.01257190, 0.01295950, 0.01334010, 0.01371380, 0.01408070, 0.01444080, 0.01479430,
   0.01514130, 0.01548170, 0.01581580, 0.01614370, 0.01646540, 0.01678110, 0.01709090},
  {0.00892800, 0.00933189, 0.00973027, 0.01012290, 0.01050960, 0.01089020, 0.01126460,
   0.01163280, 0.01199470, 0.01235040, 0.01269980, 0.01304300, 0.01338010, 0.01371110,
   0.01403610, 0.01435520, 0.01466850, 0.01497610, 0.01527800, 0.01557440, 0.01586540},
  {0.00825870, 0.00863480, 0.00900602, 0.00937212, 0.00973290, 0.01008820, 0.01043800,
   0.01078210, 0.01112060, 0.01145340, 0.01178050, 0.01210200, 0.01241790, 0.01272820,
   0.01303300, 0.01333250, 0.01362660, 0.01391540, 0.01419910, 0.01447780, 0.01475140},
  {0.00765255, 0.00800326, 0.00834965, 0.00869147, 0.00902853, 0.00936068, 0.00968781,
   0.01000990, 0.01032680, 0.01063860, 0.01094520, 0.01124660, 0.01154300, 0.01183430,
   0.01212060, 0.01240190, 0.01267830, 0.01294990, 0.01321670, 0.01347890, 0.01373650},
  {0.00710237, 0.00742986, 0.00775350, 0.00807306, 0.00838835, 0.00869923, 0.00900559,
   0.00930735, 0.00960445, 0.00989687, 0.01018460, 0.01046760, 0.01074600, 0.01101970,
   0.01128880, 0.01155340, 0.01181350, 0.01206910, 0.01232040, 0.01256730, 0.01281010},
  {0.00660196, 0.00690814, 0.00721091, 0.00751003, 0.00780533, 0.00809665, 0.00838388,
   0.00866695, 0.00894579, 0.00922037, 0.00949067, 0.00975668, 0.01001840, 0.01027590,
   0.01052920, 0.01077830, 0.01102320, 0.01126410, 0.01150090, 0.01173380, 0.01196270},
  {0.00614589, 0.00643255, 0.00671609, 0.00699641, 0.00727330, 0.00754661, 0.00781622,
   0.00808206, 0.00834405, 0.00860216, 0.00885636, 0.00910664, 0.00935302, 0.00959549,
   0.00983409, 0.01006880, 0.01029980, 0.01052690, 0.01075040, 0.01097020, 0.01118630}
}; // End of neckMaxVal

// GB 8 atom-specific screening constants and alpha/beta/gamma parameters
#define GB8_SCREEN_H 1.425952
#define GB8_SCREEN_C 1.058554
#define GB8_SCREEN_N 0.733599
#define GB8_SCREEN_O 1.061039
#define GB8_SCREEN_S -0.703469
#define GB8_SCREEN_P 0.5
#define GB8_ALPHA_H  0.788440
#define GB8_BETA_H   0.798699
#define GB8_GAMMA_H  0.437334
#define GB8_ALPHA_C  0.733756
#define GB8_BETA_C   0.506378
#define GB8_GAMMA_C  0.205844
#define GB8_ALPHA_N  0.503364
#define GB8_BETA_N   0.316828
#define GB8_GAMMA_N  0.192915
#define GB8_ALPHA_OS 0.867814
#define GB8_BETA_OS  0.876635
#define GB8_GAMMA_OS 0.387882
#define GB8_ALPHA_P  1.0
#define GB8_BETA_P   0.8
#define GB8_GAMMA_P  4.85

#endif