At present, the use of strained silicon in the design of high performance devices has been shown to be very successful. However, even if the method has found wide application many open questions still persist. A lot of interesting aspects in conjunction with dopant atoms have not yet been fully understood or even studied. The perturbed angular correlation method (PAC) has been employed to study the local lattice distortions in the near surrounding of the probe atom 111In (Cd) due to applied stress. Our current experiments reveal that the reaction of a phosphorus doped silicon lattice to mechanical strain showed strong differences depending on the direction of stress.