You don't need a library for that sensor. Wire it up according to the schematics in the data sheet, and measure voltage values using the Arduino ADC.
If you really are planning to use the "raw sensor", be certain to follow instructions:
Read the following instructions carefully before using the MiCS-6814 described here to avoid erroneous readings and to prevent the device from permanent damage.
•The sensor must be reflow soldered in a neutral atmosphere, without soldering flux vapours.
•The sensor must not be exposed to high concentrations of organic solvents, silicone vapours or cigarette-smoke in order to avoid poisoning the sensitive layer.
•Heater voltage above the specified maximum rating will destroy the sensor due to overheating.
•This sensor is to be placed in a filtered package that protects it against water and dust projections.
•SGX sensortech strongly recommends using ESD protection equipment to handle the sensor.