Clear[k1, k2, s1, s2,  z,  P, Q, R, 
        Vee, Vne, Vnn, Vex, T, d2];

z = 5.0;  w3 = Sqrt[3];
T = k1*2.25/P^2 + k2*6.75/Q^2;
Vne = -3.0*z/P - 
          3.0*(3.0 - (R/Q)^2)/Q;
d2 = 
        Sqrt[(P + Q)^2 + (P + Q + R)^2 + (P + Q)*(P + Q + 
                  R)];
Vne = 
        Vne - 6.0*z/(P + Q) - 6.0/(P + Q + R) - 
          12.0/d2;
Vee = 
        3.0*s1/P + 9.0*s2/Q + 12.0/(P + Q) + 
          12.0/(w3*(P + Q));
Vnn = 
        3.0*z/(P + Q + R) + 3.0/(w3*(P + Q + R));

(* Parameters in list c *)

c = {k1 -> 
            1.06087610, k2 ->  1.15642547, s1 ->  0.23296166, 
          s2 ->  0.32783318};

func = T + Vne + Vee + Vnn  /.  c;

t=FindMinimum[
        func, {P, 0.326}, {Q, 1.394}, {R, 0.537}]

u = t[[2]];

Vne  /. u

Vee  /. u   /.  c

Vnn  /.  u

-(Vne + Vee + Vnn)/T  /.  u  /. c

(P + Q + R)*0.529177  /.  u

\(plot1 = \(\(Graphics[{Circle[{0, 0}, P], Disk[{0, 0}, 0.1], 
	
            Circle[{\(-\((P + Q)\)\)/2, w3*\((P + Q)\)/2}, Q], 
            Circle[{\(-\((P + Q)\)\)/2, \(-w3\)*\((P + Q)\)/2}, Q], 
            Circle[{\((P + Q)\), 0}, Q], 
            Disk[{\(-\((P + Q + R)\)\)/2, w3*\((P + Q + R)\)/2}, 0.1], 
            Disk[{\(-\((P + Q + R)\)\)/2, \(-w3\)*\((P + Q + R)\)/2}, 0.1], 
            Disk[{P + Q + R, 0}, 0.1], 
			{Thickness[0.012], 
              Line[{{0, 0}, {P + Q + R, 0}}], 
              Line[{{0, 0}, {\(-\((P + Q + R)\)\)/2, w3*\((P + Q + R)\)/2}}], 
              Line[{{0, 
                    0}, {\(-\((P + Q + R)\)\)/
                      2, \(-w3\)*\((P + Q + R)\)/2}}]}}] /. \ 
        u\)\(
\)\(\ \ \ \ \ \ \ \)\)\)

Show[
        plot1,  {AspectRatio -> Automatic,  
          PlotRange -> {{-3, 3.5}, {-3, 3}}, Axes -> True, 
          GridLines -> Automatic, Frame -> True}]