Inconsistent results every time, after parallel to atomic assignment code is protected, have a big help to look at what's going on,
Code is very long, also do not know to have bosses have the patience to read...

 implicit none 
An integer n, m, node, node1, 2, ni, mj, p, q, k 
The integer I, j 

Real RCM (3) (4), RCN (3), dist 
R2f real r1f (3), (3), r3f (3), nSm (3), RJF (3, SNum_samp), r1s (3), r2s (3), r3s (3), ris (3, SNum_samp) 
Real Am, the An, lj, li, RMJ (3), rni (3), RTMPV (3) 
Real Jrm (3, maxRWG), Irn (3, maxRWG), Jlengthm (maxRWG), Ilengthn (maxRWG) 

Complex coef1, coef2 
Complex Amn_E Zji, I1ss, I2ss (3), I3ss (3), I4ss 
Complex CTMP, ctmp1 

Real, external: : re_Norm 
The integer * 4 time1, time2, time 

Call SYSTEM_CLOCK (time1) 
Write (*, *) "Start to compute the SS part of the impedance matrix, on the way... "

The allocate (SparseValue (Num_side Num_side)) 
SparseValue=https://bbs.csdn.net/topics/0 

Coef1=CMPLX (0.0, omega * MU0/* PI (16.0)) 
Coef2=CMPLX (0.0, 1.0/(4.0 * PI * * EPS0 omega)) 

! $OMP parallel do default (none) Shared (Num_Triangle triangle_centroid, triangle_area, point_cor, triangle_point, triangle_rwgs, side_index, side_length, SparseValue, threshold_R, coef1, coef2) private (n, m, node, node1, 2, ni, mj, I, j, RCM, RCN, dist, r1f, r2f, r3f, RJF, r1s, r2s, r3s, ris, Am, the An, lj, li, RMJ, rni, Jrm, Irn, Jlengthm, Ilengthn, Amn_E, CTMP, I1ss, I2ss, I3ss, I4ss) 
Do m=1, Num_Triangle 
RCM=triangle_centroid (:, m) 
Am=triangle_area (m) 

R1f=point_cor (:, triangle_point (1, m)) 
R2f=point_cor (:, triangle_point (2 m)) 
R3f=point_cor (:, triangle_point (3 m)) 

Do k=1, SNum_samp 
RJF (:, k)=epsilS * r1f + etaS (k) (k) * r2f + xiS (k) * r3f 
Enddo 

Do mj=1, triangle_rwgs (m) % N_rwg 
J=triangle_rwgs RWG (m) % (mj) 

If (side_index (3, j)==m) then 
! Flagm=1.0 
Jlengthm (mj)=side_length (j) 
The else! If (side_index (4, j)==m) then 
! Flagm=1.0 
Jlengthm (mj)=- side_length (j) 
Endif 

Node1=side_index (1, j); 2=side_index (2, j) 
Do p=1, 3 
The node=triangle_point (p, m) 
If ((node/=node1). And. (the node/=2)) exit 
Enddo 
Jrm (:, mj)=point_cor (:, node) 
Enddo 

Do n=1, Num_Triangle 
RCN=triangle_centroid (:, n) 
The An=triangle_area (n) 

R1s=point_cor (:, triangle_point (1, n))! The source triangle coordinates 
R2s=point_cor (:, triangle_point (2, n)) 
R3s=point_cor (:, triangle_point (3, n)) 

Do k=1, SNum_samp 
Ris (:, k)=epsilS * r1s + etaS (k) (k) * r2s + xiS (k) * r3s 
Enddo 

Dist=re_Norm (RCM - RCN) 

Call Comp_eltsI (I1ss, I2ss I3ss, I4ss, dist>=threshold_R, the An, RJF, ris, r1s, r2s, r3s, SNum_samp, SNum_samp, weightS, weightS) 

Do ni=1, triangle_rwgs (n) % N_rwg 
I=triangle_rwgs (n) % RWG (ni) 
If (side_index (3, I)==n) then 
! Flagn=1.0 
Ilengthn (ni)=side_length (I) 
The else! If (side_index (4, I)==n) then 
! Flagn=1.0 
Ilengthn (ni)=- side_length (I) 
Endif 

Node1=side_index (1, I); 2=side_index (2, I) 
Do q=1, 3 
The node=triangle_point (q, n) 
If ((node/=node1). And. (the node/=2)) exit 
Enddo 
Irn (:, ni)=point_cor (:, node) 
Enddo 

Do mj=1, triangle_rwgs (m) % N_rwg 
J=triangle_rwgs RWG (m) % (mj) 
RMJ=Jrm (:, mj) 
Lj=Jlengthm (mj) 

CTMP=coef1 * (I4ss - dot_product (RMJ, I3ss)) - coef2 * I1ss 

Do ni=1, triangle_rwgs (n) % N_rwg 
I=triangle_rwgs (n) % RWG (ni) 

Rni=Irn (:, ni) 
Li=Ilengthn (ni) 

Li Amn_E=lj * * (coef1 * (dot_product (RMJ, rni) * I1ss - dot_product (rni, I2ss)) + CTMP) 

! $OMP atomic 
SparseValue (I, j)=SparseValue (I, j) + Amn_E 

Enddo 
Enddo 
Enddo 

Enddo 
! $OMP end parallel do