user: What would the C source look like for the assembly code provided here?

```asm
<Slater_1S_2S>:
  endbr64
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x40,%rsp
  movsd  %xmm0,(%rsp)
  movsd  %xmm1,0x8(%rsp)
  movsd  %xmm2,0x10(%rsp)
  ucomisd %xmm1,%xmm2
  jp     L25
  movapd %xmm2,%xmm6
  jne    L25
  movapd %xmm0,%xmm2
  addsd  %xmm0,%xmm2
  movapd %xmm2,%xmm5
  mulsd  %xmm6,%xmm5
  movq   %xmm5,%rbp
  movapd %xmm5,%xmm1
  mov    D561(%rip),%rax
  movq   %rax,%xmm0
  call   <pow@plt>
  pxor   %xmm1,%xmm1
  cvtsi2sd %eax,%xmm1
  mulsd  D640(%rip),%xmm1
  subsd  D640(%rip),%xmm1
  movsd  (%rsp),%xmm4
  movapd %xmm4,%xmm0
  mulsd  D510(%rip),%xmm0
  mulsd  0x10(%rsp),%xmm0
  subsd  %xmm0,%xmm1
  movq   %xmm1,%rbx
  mov    D398(%rip),%rax
  movq   %rax,%xmm1
  movapd %xmm4,%xmm0
  call   <pow@plt>
  mov    %eax,%r12d
  mov    D398(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x10(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm0,%xmm0
  cvtsi2sd %r12d,%xmm0
  mulsd  D490(%rip),%xmm0
  pxor   %xmm1,%xmm1
  cvtsi2sd %eax,%xmm1
  mulsd  %xmm1,%xmm0
  movq   %rbx,%xmm5
  subsd  %xmm0,%xmm5
  movq   %xmm5,%rbx
  mov    D648(%rip),%rax
  movq   %rax,%xmm1
  movsd  (%rsp),%xmm0
  call   <pow@plt>
  mov    %eax,%r12d
  mov    D648(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x10(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm0,%xmm0
  cvtsi2sd %r12d,%xmm0
  mulsd  D329(%rip),%xmm0
  pxor   %xmm1,%xmm1
  cvtsi2sd %eax,%xmm1
  mulsd  %xmm1,%xmm0
  movq   %rbx,%xmm5
  subsd  %xmm0,%xmm5
  movq   %xmm5,%rbx
  mov    D191(%rip),%rax
  movq   %rax,%xmm1
  movsd  (%rsp),%xmm0
  call   <pow@plt>
  mov    %eax,%r12d
  mov    D191(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x10(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm0,%xmm0
  cvtsi2sd %r12d,%xmm0
  mulsd  D148(%rip),%xmm0
  pxor   %xmm1,%xmm1
  cvtsi2sd %eax,%xmm1
  mulsd  %xmm1,%xmm0
  movq   %rbx,%xmm7
  subsd  %xmm0,%xmm7
  movq   %xmm7,%rbx
  mov    D260(%rip),%rax
  movq   %rax,%xmm1
  movsd  (%rsp),%xmm0
  call   <pow@plt>
  mov    %eax,%r12d
  mov    D260(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x10(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm0,%xmm0
  cvtsi2sd %r12d,%xmm0
  mulsd  D191(%rip),%xmm0
  pxor   %xmm1,%xmm1
  cvtsi2sd %eax,%xmm1
  mulsd  %xmm1,%xmm0
  movq   %rbx,%xmm2
  subsd  %xmm0,%xmm2
  movq   %xmm2,%rbx
  movq   %rbp,%xmm1
  mov    D561(%rip),%rax
  movq   %rax,%xmm0
  call   <pow@plt>
  pxor   %xmm1,%xmm1
  cvtsi2sd %eax,%xmm1
  mulsd  D640(%rip),%xmm1
  mulsd  (%rsp),%xmm1
  movq   %rbx,%xmm0
  divsd  %xmm1,%xmm0
L16:
  add    $0x40,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  ret
L25:
  movsd  (%rsp),%xmm3
  movapd %xmm3,%xmm4
  addsd  %xmm3,%xmm4
  movsd  0x10(%rsp),%xmm0
  addsd  0x8(%rsp),%xmm0
  movapd %xmm0,%xmm7
  movsd  %xmm4,0x18(%rsp)
  mulsd  %xmm4,%xmm7
  movq   %xmm7,%r14
  movapd %xmm7,%xmm1
  mov    D561(%rip),%rax
  movq   %rax,%xmm0
  call   <pow@plt>
  mov    %eax,%ebp
  mov    D398(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x10(%rsp),%xmm0
  call   <pow@plt>
  mov    %eax,%ebx
  mov    D398(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x8(%rsp),%xmm0
  call   <pow@plt>
  sub    %eax,%ebx
  pxor   %xmm0,%xmm0
  cvtsi2sd %ebx,%xmm0
  mov    D260(%rip),%rax
  movq   %rax,%xmm1
  call   <pow@plt>
  pxor   %xmm0,%xmm0
  cvtsi2sd %ebp,%xmm0
  mulsd  D286(%rip),%xmm0
  pxor   %xmm1,%xmm1
  cvtsi2sd %eax,%xmm1
  movapd %xmm0,%xmm7
  mulsd  %xmm1,%xmm7
  movsd  %xmm7,0x20(%rsp)
  movsd  0x18(%rsp),%xmm1
  mulsd  0x8(%rsp),%xmm1
  mov    D561(%rip),%rax
  movq   %rax,%xmm0
  call   <pow@plt>
  mov    %eax,%ebx
  mov    D286(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x8(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm0,%xmm0
  cvtsi2sd %ebx,%xmm0
  mulsd  D286(%rip),%xmm0
  pxor   %xmm1,%xmm1
  cvtsi2sd %eax,%xmm1
  movapd %xmm0,%xmm2
  mulsd  %xmm1,%xmm2
  movsd  %xmm2,0x28(%rsp)
  mov    D191(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x10(%rsp),%xmm0
  call   <pow@plt>
  mov    %eax,%ebx
  mov    D260(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x10(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm1,%xmm1
  cvtsi2sd %ebx,%xmm1
  mulsd  D247(%rip),%xmm1
  pxor   %xmm0,%xmm0
  cvtsi2sd %eax,%xmm0
  mulsd  (%rsp),%xmm0
  movapd %xmm1,%xmm8
  subsd  %xmm0,%xmm8
  movq   %xmm8,%rbx
  mov    D398(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x10(%rsp),%xmm0
  call   <pow@plt>
  mov    %eax,%ebp
  mov    D398(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x8(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm0,%xmm0
  cvtsi2sd %ebp,%xmm0
  mulsd  D260(%rip),%xmm0
  pxor   %xmm1,%xmm1
  cvtsi2sd %eax,%xmm1
  mulsd  %xmm1,%xmm0
  movq   %rbx,%xmm9
  subsd  %xmm0,%xmm9
  movsd  %xmm9,0x30(%rsp)
  mov    D191(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x8(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm0,%xmm0
  cvtsi2sd %eax,%xmm0
  movapd %xmm0,%xmm10
  addsd  0x30(%rsp),%xmm10
  movsd  %xmm10,0x30(%rsp)
  movsd  0x10(%rsp),%xmm5
  mulsd  (%rsp),%xmm5
  movsd  %xmm5,0x38(%rsp)
  mov    D191(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x8(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm0,%xmm0
  cvtsi2sd %eax,%xmm0
  mulsd  0x38(%rsp),%xmm0
  addsd  0x30(%rsp),%xmm0
  mulsd  0x28(%rsp),%xmm0
  movapd %xmm0,%xmm2
  addsd  0x20(%rsp),%xmm2
  movsd  %xmm2,0x20(%rsp)
  movsd  0x18(%rsp),%xmm1
  mulsd  0x10(%rsp),%xmm1
  mov    D561(%rip),%rax
  movq   %rax,%xmm0
  call   <pow@plt>
  mov    %eax,%ebx
  mov    D191(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x10(%rsp),%xmm0
  call   <pow@plt>
  mov    %eax,%ebp
  mov    D286(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x10(%rsp),%xmm0
  call   <pow@plt>
  mov    %eax,%r12d
  mov    D398(%rip),%rax
  movq   %rax,%xmm1
  movsd  (%rsp),%xmm0
  call   <pow@plt>
  mov    %eax,%r13d
  mov    D398(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x8(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm1,%xmm1
  cvtsi2sd %r13d,%xmm1
  mulsd  D286(%rip),%xmm1
  pxor   %xmm0,%xmm0
  cvtsi2sd %eax,%xmm0
  mulsd  %xmm0,%xmm1
  movsd  (%rsp),%xmm3
  movapd %xmm3,%xmm5
  mulsd  D159(%rip),%xmm5
  movapd %xmm5,%xmm0
  mulsd  0x8(%rsp),%xmm0
  addsd  D286(%rip),%xmm0
  addsd  %xmm0,%xmm1
  movsd  %xmm1,0x18(%rsp)
  mov    D648(%rip),%rax
  movq   %rax,%xmm1
  movapd %xmm3,%xmm0
  call   <pow@plt>
  mov    %eax,%r13d
  mov    D648(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x8(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm0,%xmm0
  cvtsi2sd %r13d,%xmm0
  addsd  %xmm0,%xmm0
  pxor   %xmm1,%xmm1
  cvtsi2sd %eax,%xmm1
  mulsd  %xmm1,%xmm0
  addsd  0x18(%rsp),%xmm0
  pxor   %xmm1,%xmm1
  cvtsi2sd %r12d,%xmm1
  movapd %xmm0,%xmm4
  mulsd  %xmm1,%xmm4
  movq   %xmm4,%r12
  mov    D191(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x10(%rsp),%xmm0
  call   <pow@plt>
  mov    %eax,%r13d
  mov    D398(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x8(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm0,%xmm0
  cvtsi2sd %r13d,%xmm0
  mulsd  D648(%rip),%xmm0
  pxor   %xmm1,%xmm1
  cvtsi2sd %eax,%xmm1
  movapd %xmm0,%xmm4
  mulsd  %xmm1,%xmm4
  movsd  %xmm4,0x18(%rsp)
  mov    D398(%rip),%rax
  movq   %rax,%xmm1
  movsd  (%rsp),%xmm0
  call   <pow@plt>
  mov    %eax,%r13d
  mov    D398(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x8(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm1,%xmm1
  cvtsi2sd %r13d,%xmm1
  movsd  D266(%rip),%xmm2
  mulsd  %xmm2,%xmm1
  pxor   %xmm0,%xmm0
  cvtsi2sd %eax,%xmm0
  mulsd  %xmm0,%xmm1
  movsd  (%rsp),%xmm3
  movapd %xmm3,%xmm6
  mulsd  D701(%rip),%xmm6
  movapd %xmm6,%xmm0
  mulsd  0x8(%rsp),%xmm0
  addsd  %xmm2,%xmm0
  addsd  %xmm0,%xmm1
  movsd  %xmm1,0x28(%rsp)
  mov    D648(%rip),%rax
  movq   %rax,%xmm1
  movapd %xmm3,%xmm0
  call   <pow@plt>
  mov    %eax,%r13d
  mov    D648(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x8(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm0,%xmm0
  cvtsi2sd %r13d,%xmm0
  addsd  %xmm0,%xmm0
  pxor   %xmm1,%xmm1
  cvtsi2sd %eax,%xmm1
  mulsd  %xmm1,%xmm0
  addsd  0x28(%rsp),%xmm0
  mulsd  0x18(%rsp),%xmm0
  movq   %r12,%xmm4
  subsd  %xmm0,%xmm4
  movsd  %xmm4,0x18(%rsp)
  mov    D398(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x10(%rsp),%xmm0
  call   <pow@plt>
  mov    %eax,%r12d
  mov    D191(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x8(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm0,%xmm0
  cvtsi2sd %r12d,%xmm0
  mulsd  D648(%rip),%xmm0
  pxor   %xmm1,%xmm1
  cvtsi2sd %eax,%xmm1
  movapd %xmm0,%xmm11
  mulsd  %xmm1,%xmm11
  movsd  %xmm11,0x28(%rsp)
  mov    D398(%rip),%rax
  movq   %rax,%xmm1
  movsd  (%rsp),%xmm0
  call   <pow@plt>
  mov    %eax,%r12d
  mov    D398(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x8(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm1,%xmm1
  cvtsi2sd %r12d,%xmm1
  mulsd  D403(%rip),%xmm1
  pxor   %xmm0,%xmm0
  cvtsi2sd %eax,%xmm0
  mulsd  %xmm0,%xmm1
  movsd  (%rsp),%xmm3
  movapd %xmm3,%xmm7
  mulsd  D157(%rip),%xmm7
  movapd %xmm7,%xmm0
  mulsd  0x8(%rsp),%xmm0
  addsd  D725(%rip),%xmm0
  addsd  %xmm0,%xmm1
  movsd  %xmm1,0x30(%rsp)
  mov    D648(%rip),%rax
  movq   %rax,%xmm1
  movapd %xmm3,%xmm0
  call   <pow@plt>
  mov    %eax,%r12d
  mov    D648(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x8(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm0,%xmm0
  cvtsi2sd %r12d,%xmm0
  addsd  %xmm0,%xmm0
  pxor   %xmm1,%xmm1
  cvtsi2sd %eax,%xmm1
  mulsd  %xmm1,%xmm0
  addsd  0x30(%rsp),%xmm0
  mulsd  0x28(%rsp),%xmm0
  movapd %xmm0,%xmm4
  addsd  0x18(%rsp),%xmm4
  movsd  %xmm4,0x18(%rsp)
  mov    D286(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x8(%rsp),%xmm0
  call   <pow@plt>
  mov    %eax,%r12d
  mov    D398(%rip),%rax
  movq   %rax,%xmm1
  movsd  (%rsp),%xmm0
  call   <pow@plt>
  mov    %eax,%r13d
  mov    D398(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x8(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm1,%xmm1
  cvtsi2sd %r13d,%xmm1
  mulsd  D305(%rip),%xmm1
  pxor   %xmm0,%xmm0
  cvtsi2sd %eax,%xmm0
  mulsd  %xmm0,%xmm1
  movsd  (%rsp),%xmm3
  movapd %xmm3,%xmm5
  mulsd  D530(%rip),%xmm5
  movapd %xmm5,%xmm0
  mulsd  0x8(%rsp),%xmm0
  addsd  D494(%rip),%xmm0
  movapd %xmm1,%xmm6
  addsd  %xmm0,%xmm6
  movsd  %xmm6,0x28(%rsp)
  mov    D648(%rip),%rax
  movq   %rax,%xmm1
  movapd %xmm3,%xmm0
  call   <pow@plt>
  mov    %eax,%r13d
  mov    D648(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x8(%rsp),%xmm0
  call   <pow@plt>
  pxor   %xmm0,%xmm0
  cvtsi2sd %r13d,%xmm0
  addsd  %xmm0,%xmm0
  pxor   %xmm1,%xmm1
  cvtsi2sd %eax,%xmm1
  mulsd  %xmm1,%xmm0
  addsd  0x28(%rsp),%xmm0
  pxor   %xmm1,%xmm1
  cvtsi2sd %r12d,%xmm1
  mulsd  %xmm1,%xmm0
  movsd  0x18(%rsp),%xmm1
  subsd  %xmm0,%xmm1
  imul   %ebp,%ebx
  pxor   %xmm0,%xmm0
  cvtsi2sd %ebx,%xmm0
  mulsd  %xmm1,%xmm0
  movsd  0x20(%rsp),%xmm2
  subsd  %xmm0,%xmm2
  movq   %xmm2,%rbx
  movq   %r14,%xmm1
  mov    D561(%rip),%rax
  movq   %rax,%xmm0
  call   <pow@plt>
  pxor   %xmm0,%xmm0
  cvtsi2sd %eax,%xmm0
  mulsd  D286(%rip),%xmm0
  movapd %xmm0,%xmm2
  mulsd  (%rsp),%xmm2
  movsd  %xmm2,(%rsp)
  mov    D398(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x10(%rsp),%xmm0
  call   <pow@plt>
  mov    %eax,%ebp
  mov    D398(%rip),%rax
  movq   %rax,%xmm1
  movsd  0x8(%rsp),%xmm0
  call   <pow@plt>
  sub    %eax,%ebp
  pxor   %xmm0,%xmm0
  cvtsi2sd %ebp,%xmm0
  mov    D260(%rip),%rax
  movq   %rax,%xmm1
  call   <pow@plt>
  pxor   %xmm1,%xmm1
  cvtsi2sd %eax,%xmm1
  mulsd  (%rsp),%xmm1
  movq   %rbx,%xmm0
  divsd  %xmm1,%xmm0
  jmp    L16
```

tool_calls: name: unpack_data
arguments: data_label: D561
data_type: f64
name: unpack_data
arguments: data_label: D640
data_type: f64
name: unpack_data
arguments: data_label: D510
data_type: f64
name: unpack_data
arguments: data_label: D398
data_type: f64
name: unpack_data
arguments: data_label: D490
data_type: f64
name: unpack_data
arguments: data_label: D648
data_type: f64
name: unpack_data
arguments: data_label: D329
data_type: f64
name: unpack_data
arguments: data_label: D191
data_type: f64
name: unpack_data
arguments: data_label: D148
data_type: f64
name: unpack_data
arguments: data_label: D260
data_type: f64
name: unpack_data
arguments: data_label: D286
data_type: f64
name: unpack_data
arguments: data_label: D247
data_type: byte[8]
name: unpack_data
arguments: data_label: D159
data_type: f64
name: unpack_data
arguments: data_label: D266
data_type: f64
name: unpack_data
arguments: data_label: D701
data_type: f64
name: unpack_data
arguments: data_label: D403
data_type: f64
name: unpack_data
arguments: data_label: D157
data_type: f64
name: unpack_data
arguments: data_label: D725
data_type: f64
name: unpack_data
arguments: data_label: D305
data_type: f64
name: unpack_data
arguments: data_label: D530
data_type: f64
name: unpack_data
arguments: data_label: D494
data_type: f64

tool: D561: 2.718281828459045

tool: D640: 240

tool: D510: 375

tool: D398: 2

tool: D490: 270

tool: D648: 3

tool: D329: 115

tool: D191: 4

tool: D148: 30

tool: D260: 5

tool: D286: 6

tool: {"D247": [0x00,0x00,0x00,0x00,0x00,0x00,0x10,0xc0]}

tool: D159: 9

tool: D266: 10

tool: D701: 15

tool: D403: 14

tool: D157: 33

tool: D725: 20

tool: D305: 18

tool: D530: 63

tool: D494: 84

assistant: ```c
double Slater_1S_2S(double rij, double xij, double xii) {
  double S;
  if (xii == xij) {
    S = (-240.0 + 240.0 * (pow((double)(2.71828182845904523536029), (double)(2.0 * rij * xii))) - 375.0 * rij * xii - 270.0 * (pow((double)(rij), (double)(2.0))) * (pow((double)(xii), (double)(2.0))) - 115.0 * (pow((double)(rij), (double)(3.0))) * (pow((double)(xii), (double)(3.0))) - 30.0 * (pow((double)(rij), (double)(4.0))) * (pow((double)(xii), (double)(4.0))) - 4.0 * (pow((double)(rij), (double)(5.0))) * (pow((double)(xii), (double)(5.0)))) / (240. * (pow((double)(2.71828182845904523536029), (double)(2.0 * rij * xii))) * rij);
  } else {
    S = (6.0 * (pow((double)(2.71828182845904523536029), (double)(2.0 * rij * (xii + xij)))) * (pow((double)((pow((double)(xii), (double)(2.0))) - (pow((double)(xij), (double)(2.0)))), (double)(5.0))) + 6.0 * (pow((double)(2.71828182845904523536029), (double)(2.0 * rij * xij))) * (pow((double)(xij), (double)(6.0))) * (-4.0 * (pow((double)(xii), (double)(4.0))) - rij * (pow((double)(xii), (double)(5.0))) - 5.0 * (pow((double)(xii), (double)(2.0))) * (pow((double)(xij), (double)(2.0))) + (pow((double)(xij), (double)(4.0))) + rij * xii * (pow((double)(xij), (double)(4.0)))) - (pow((double)(2.71828182845904523536029), (double)(2.0 * rij * xii))) * (pow((double)(xii), (double)(4.0))) * ((pow((double)(xii), (double)(6.0))) * (6.0 + 9.0 * rij * xij + 6.0 * (pow((double)(rij), (double)(2.0))) * (pow((double)(xij), (double)(2.0))) + 2.0 * (pow((double)(rij), (double)(3.0))) * (pow((double)(xij), (double)(3.0)))) - 3.0 * (pow((double)(xii), (double)(4.0))) * (pow((double)(xij), (double)(2.0))) * (10.0 + 15.0 * rij * xij + 10.0 * (pow((double)(rij), (double)(2.0))) * (pow((double)(xij), (double)(2.0))) + 2.0 * (pow((double)(rij), (double)(3.0))) * (pow((double)(xij), (double)(3.0)))) + 3.0 * (pow((double)(xii), (double)(2.0))) * (pow((double)(xij), (double)(4.0))) * (20.0 + 33.0 * rij * xij + 14.0 * (pow((double)(rij), (double)(2.0))) * (pow((double)(xij), (double)(2.0))) + 2.0 * (pow((double)(rij), (double)(3.0))) * (pow((double)(xij), (double)(3.0)))) - (pow((double)(xij), (double)(6.0))) * (84.0 + 63.0 * rij * xij + 18.0 * (pow((double)(rij), (double)(2.0))) * (pow((double)(xij), (double)(2.0))) + 2.0 * (pow((double)(rij), (double)(3.0))) * (pow((double)(xij), (double)(3.0)))))) / (6. * (pow((double)(2.71828182845904523536029), (double)(2.0 * rij * (xii + xij)))) * rij * (pow((double)((pow((double)(xii), (double)(2.0))) - (pow((double)(xij), (double)(2.0)))), (double)(5.0))));
  }
  return S;
}
```