Program.cs

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.


using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using Microsoft.Quantum.Simulation.Core;
using Microsoft.Quantum.Simulation.Simulators;

namespace Microsoft.Quantum.Samples.H2Simulation
{
 class Program
 {
 static void Main(string[] args)
 {

 // We begin by making an instance of the simulator that we will use to run our Q# code.
 using (var qsim = new QuantumSimulator()) {

 #region Basic Definitions

 // Next, we give C# names to each operation defined in Q#.
 // In doing so, we ask the simulator to give us each operation
 // so that it has an opportunity to override operation definitions.
 var H2EstimateEnergyRPE = qsim.Get<H2EstimateEnergyRPE, H2EstimateEnergyRPE>();
 var H2BondLengths = qsim.Get<H2BondLengths, H2BondLengths>();

 #endregion

 #region Calling into Q#

 // To call a Q# operation that takes unit `()` as its input, we need to grab
 // the QVoid.Instance value.
 var bondLengths = H2BondLengths.Body.Invoke(QVoid.Instance);

 // In Q#, we defined the operation that performs the actual estimation;
 // we can call it here, giving a structure tuple that corresponds to the
 // C# ValueTuple that it takes as its input. Since the Q# operation
 // has type (idxBondLength : Int, nBitsPrecision : Int, trotterStepSize : Double) => (Double),
 // we pass the index along with that we want six bits of precision and
 // step size of 1.
 //
 // The result of calling H2EstimateEnergyRPE is a Double, so we can minimize over
 // that to deal with the possibility that we accidently entered into the excited
 // state instead of the ground state of interest.
 Func<int, Double> estAtBondLength = (idx) => Enumerable.Min(
 from idxRep in Enumerable.Range(0, 3)
 select H2EstimateEnergyRPE.Body.Invoke((idx, 6, 1.0))
 );

 // We are now equipped to run the Q# simulation at each bond length
 // and print the answers out to the console.
 foreach (var idxBond in Enumerable.Range(0, 54))
 {
 System.Console.WriteLine($"Estimating at bond length {bondLengths[idxBond]}:");
 var est = estAtBondLength(idxBond);
 System.Console.WriteLine($"\tEst: {est}\n");
 }

 #endregion

 }

 Console.WriteLine("Press Enter to continue...");
 Console.ReadLine();
 }
 }
}