i want to apply a gate voltage of +0.1V and the bias voltage range is from 0 to +0.7(in case of GNRFET).i wanted to know that when i give +values of these voltages in the required fields in ATK the results are obtained for the negative values....thus how to obtain the results for the +values of Vbias and Vgate...since that is what is neede(symmetrise option is available but i need it for the value of voltage that i apply for i.e for example if i give Vbias=0.1,the value of current and the plot is obtained for -0.1 in the I-V curve)