package Sci
@ISA = qw()

sub a0
return $a0;

sub u0
return $u0;

sub e0
return $e0;

sub pi
return $pi;

sub ub
return "9.27402e-24 J/T";

sub un
return "5.050787e-27 J/T";

sub NA
return $NA;

sub R
return $R;

sub kB
return $kB;

sub F
return $F;

sub g
return $g;

sub c
return $c;

sub me
return $me;

sub mn
return $mn;

sub mp
return $mp;

sub e
return $e;

sub h
return $h;

sub h_bar
return $h_bar;

sub hbar
return $h_bar;

sub G
return $G;

sub Debye
return $Debye;

sub todeg
return $todeg;

sub torad
return $torad;

sub HartreeToeV
return $HartreeToeV;

sub RyToeV
return $RyToeV;

sub eVToHartree
return 1.0/$a;

sub eVToRy
return 1.0/$RyToeV;

sub DayToSecond
return $DayToSecond;

sub SecondToDay
return $SecondToDay;

sub AstronomicalUnit
return $AstronomicalUnit;

sub eVTonm
return (h() / ($_[0]*e())) * cI() * 1e9;

sub mod
my ($val, $max) = @_;
return $val;

sub tan
return sin($_[0]) / cos($_[0]);

sub dtan
return tan($_[0]*$torad);

sub dcos
return cos($_[0]*$torad);

sub dsin
return sin($_[0]*$torad);

sub asin
return atan2($sinQ, $cosQ);

sub acos
my ($cosa) = @_;
return $pi/2.0 if(abs($cosa) < 0.000001);
return 0.0 if(abs($cosa - 1.0) < 0.000001);
return $pi if(abs($cosa + 1.0) < 0.000001);
return 0.0 if($sina <= 0.0);
return atan2($sina, $cosa);

sub atan
return atan2($_[0], 1.0);

sub dacos
return acos($_[0])*$todeg;

sub dasin
return asin($_[0])*$todeg;

sub datan
return atan($_[0])*$todeg;

sub cosh

sub sinh

sub tanh
return sinh($_[0]) / cosh($_[0]);

sub log10
return log($_[0]) * 0.4342944819;

sub CircleArea
return $_[0]*$_[0]*$pi;

sub XRDDtoQ
return asin(1.5405/2/$_[0])*$todeg/2.0;

sub FuncLinear
return $_[0];

sub FuncMinus
return -$_[0];

sub FuncLog10
return log10($_[0]) if($_[0] > 0);

sub FuncLog10Abs
return log10(abs($_[0])) if($_[0] != 0.0);

sub FuncLn
return log($_[0]) if($_[0] > 0);

sub FuncLnAbs
return log(abs($_[0])) if($_[0] != 0);

sub FuncInverse
return 1 / $_[0] if($_[0] != 0);

sub FuncPower10
return 10**($_[0]);

sub FuncPower10Abs
return 10**(abs($_[0]));

sub FuncExp
return exp($_[0]);

sub FuncExpAbs
return exp(abs($_[0]));

sub Round
my ($val, $digit) = @_;
return int($val*$k + 0.1) / $k;

sub Polynomial
my ($x, $m, @c) = @_;
return $v;

sub Gaussian
my ($x, $x0, $whalf) = @_;
return $A * exp(-$X*$X);

sub Lorentzian
my ($x, $x0, $whalf) = @_;
return $A / (1.0 + $X*$X);

sub GaussLorentz
my ($x, $x0, $C0, $WL, $GFraction, $GWRatio) = @_;
return $y;

sub erfc
my ($x) = @_;
return undef if($wx < 0.0);
return 0.0 if($wx ==  0.0);
return 1.0 if($wx >= 10.0);
return 1.0 - 1.0 / $w;

sub Gamma
my ($x) = @_;
return undef if($wx <= 0.0 or $wx >= 34.0);
return $w1 * $w / $wx;

sub LegendrePolynomial
my ($x, $n) = @_;
return undef if($n < 0);
return 1.0 if($n == 0);
return $x if($n == 1);
return $p2;

sub ElectroneVTonm
my ($ElectronEnergy) = @_;
return sqrt($h * $h / 2.0 / $me / $ElectronEnergy / $e) * 1.0e9;

sub NormalizeVector
my ($pv1, $l) = @_;
return undef if($L2 < 1.0e-15);
return \@NormalizeV;

sub VectorProduct
my ($pv1, $pv2, $k) = @_;

sub ScalarProduct
my ($pv1, $pv2) = @_;
return &InnerProduct($pv1, $pv2);

sub InnerProduct
my ($pv1, $pv2) = @_;
return $val;

sub CalVectorAngle
my ($pv1, $pv2) = @_;
return undef if(abs($l1) < 1.0e-15);
return undef if(abs($l2) < 1.0e-15);
return $todeg * acos($cosQ);

sub FermiDiracDistribution
my ($x, $x0) = @_;
return &FD($x, $x0);

sub FD
my ($x, $x0) = @_;
return 1.0 / (1.0 + exp($x-$x0));

sub PoweredFermiDirac
my ($x, $x0, $r) = @_;
return 1.0 / (1.0 + exp($x-$x0));
return $x**$r / (1.0 + exp($x-$x0));

sub FermiDiracIntegralByNumericalIntegration
my ($xi, $r, $h, $xmax) = @_;
return Algorism::SinglePointIntegrateByConstantStepSimpson($i, $h, \@y);

sub FermiDiracIntegral
my ($xi, $r) = @_;
return &DegenerateFermiDirac($xi, $r)    if($xi >= 20.0);
return &NonDegenerateFermiDirac($xi, $r) if($xi < -0.1);
return &IntermediateFermiDirac($xi, $r);

sub DegenerateFermiDirac
my ($xi, $r) = @_;
return $gi * (1.0 + 2.0 * ($r+1.0) * $gs);

sub NonDegenerateFermiDirac
my ($xi, $r) = @_;
return $sum * Gamma($r+1.0);

sub IntermediateFermiDirac
my ($xi, $r) = @_;
return &head($xi, $r) + &tail($xi, $r);

sub head
my ($xi, $r) = @_;
return $sum * $g / $gp * 0.1**($r+1.0);

sub tail
my ($xi, $r) = @_;
return $sum;

sub FermiDiracSimpson
my ($xi, $r, $a, $b, $n) = @_;
return ($sa - $sb + 2.0*$s2 + 4.0*$s4) * $dx / 3.0;

sub BlackbodyRadiationBynm
my ($l, $T) = @_;
return $KBBRadiation / $lambda2 / $lambda2 / $lambda / ($ex - 1.0);

sub c_gamma
my ($x) = @_;
return 2.50663 * exp($y) / $q;