Need assistance for OP AMP -20 to +200C

I've created in NI Multisim 11 project PT1000 and OP Amp TLC271CP for 
measuring temperature from-20C to +200 C. It should formula for 
calculation Vout and to check whether this model can work in reality. I 
am not electrician but my Hobby's electronics. Intervals Vout (ADC) is 
0-5 V. Microcontroller was ATMega 16, but that does not meet, if 
resolution ADC ATMega 16 is not good I think to use SPI MCP3201 12-bit 
ADC.  Further should formula for calculation RT (R7) on bases Vout.