Enerf[[Rho]f_, [Zeta]f1_, [Zeta]f2_, angf1_, angf2_,
   zf_, [Gamma]f_, mf_] := Module[{},
   [Zeta]f = {[Zeta]f1, [Zeta]f2};
   mf1 = mf;
   Angf[dona_] := If[dona == 1, angf1*Pi/180., angf2*Pi/180., 0];
   d[Phi]f = Angf[2] - Angf[1];
   [Xi]ff =
    Sqrt[[Zeta]f1^2 + [Zeta]f2^2 -
     2*[Zeta]f2*[Zeta]f1*Cos[d[Phi]f]];
   ConstanteDiagonalf = !(
*UnderoverscriptBox[([Sum]), (j = 1), (2)](NIntegrate[
*FractionBox[(-2), (2*Pi*
*SqrtBox[(
*SuperscriptBox[([Rho]f), (2)] +
*SuperscriptBox[(([Zeta]f[([j])])), (2)] -
          2  [Rho]f*[Zeta]f[([j])] Cos[[CurlyPhi] - Angf[j]] +
*SuperscriptBox[((zf)), (2)])])], {[CurlyPhi], 0, 2  Pi}]));

   akf = ParallelTable[If[k - kp == 0,
      k^2/[Rho]f^2 + [Gamma]f* k + ( ([Gamma]f)^2 [Rho]f^2)/4 +
       ConstanteDiagonalf + 2/[Xi]ff,

      NIntegrate[(-2 Exp[I (k - kp)*[CurlyPhi]])/(
        2*Pi*Sqrt[[Rho]f^2 + [Zeta]f1^2 -

          2*[Rho]f*[Zeta]f1 Cos[[CurlyPhi] -
             Angf[1]] + (zf)^2]), {[CurlyPhi], 0, 2 Pi}] -
       NIntegrate[(-2 Exp[I (k - kp)*[CurlyPhi]])/(
        2*Pi*Sqrt[[Rho]f^2 + [Zeta]f2^2 -
          2*[Rho]f*[Zeta]f2*
           Cos[[CurlyPhi] - Angf[2]] + (zf)^2]), {[CurlyPhi], 0,
         2 Pi}]

      ], {k, -mf1, mf1, 1}, {kp, -mf1, mf1, 1}];
   valoresf = Eigensystem[akf];
   ValoresTf = Transpose[SortBy[Transpose[valoresf], #1 &]];

   {ValoresTf[[1]], 5.8*ValoresTf[[1]]} // MatrixForm
   ];

Enerf[1, 0.9, 0.9, -120, 90, 0, 0, 4]