Troubles using RigidBodyTransMover and RigidBodyPerturbMover

Goodmorning,

I’m currently experiencing some troubles while using the RigidBodyMovers and I hope someone could explain me this strange problem. I perform a rigid body move and calculates its energy. But the result is different if I evaluate the energy after having stored the pose in a .pdb. Here is the code.


// Creating the poses and the scoring function
core::pose::PoseOP pose = new core::pose::Pose();
core::scoring::ScoreFunctionOP score_fxn = core::scoring::ScoreFunctionFactory::create_score_function("standard");
makePoseFromSequence(pose, String("AAAAAAAAAAAAAAAAAAAA"));
core::pose::PoseOP result3 = new core::pose::Pose((*pose));
// Initializing the jump and the foldtree
core::kinematics::FoldTree foldTree = result3->fold_tree();
foldTree.new_jump(5, 15, 10);
result3->fold_tree(foldTree);
// Performing the move
protocols::moves::RigidBodyTransMoverOP mover = new protocols::moves::RigidBodyTransMover((*result3), 1);
mover->step_size(1);
mover->apply((*result3));
// Restoring the foldtree of the jump
foldTree.delete_jump_and_intervening_cutpoint(1);
result3->fold_tree(foldTree);
// Outputting results
cout << "RBT energy final : " << (*score_fxn)(*result3) << endl;
core::io::pdb::dump_pdb((*result3), "rbt_final_tmp.pdb");
core::pose::PoseOP result3tmp = new core::pose::Pose("rbt_final_tmp.pdb");
cout << "RBT energy final from PDB: " << (*score_fxn)(*result3tmp) << endl;


This code returns :

RBT energy final : 112008
RBT energy final from PDB: 112013

The difference is tiny but it exists. Do I do something wrong with the movers or is this phenomenon explainable?

Thank you.
Alejandro