with the 1 ohm resistor on the noninverting input, and 1k on the inverting input, you have offset from the unbalanced input currents. change the 1 ohm resistor for a 1k (910 ohms would actually be closer to balancing out the bias currents, but 1k will work). right now you have the bias currents impressing a voltage across the resistors, 150pV on one input (+) and 0.15mV on the other (-) giving 0.14995 mV offset at the inputs. multiply that by 100 and you get 14.995mV offset. this is using the worst-case bias current values in the data sheet, but you can see how this develops offset.