Display time in higher precision

src/tensormatrix_mpi.cpp

@@ -148,7 +148,7 @@ int main( int argc, char** argv ){
         std::cout << "Tpara3=" << Tpara << ";" << std::endl;
         std::cout << "Tseq=" << Tseq << ";" << std::endl;
 #endif
-        std::cout.precision( 2 );
+        std::cout.precision( 4 );
         std::cout << "Time: ";
         std::cout << "parallel    " << ( tv_para - tv_start ) / 1e6 << "   ";
 #if DEBUG