Ab Initio Molecular Dynamics Simulations and Vibrational Frequency Calculations of Species in Liquid-Liquid Phase Separated MgSO<sub>4</sub> Solution at 543 K

<div>Schematic comparison of prenucleation, CNT, and spinodal decomposition. <svg height="6.1673pt" id="M119" style="vertical-align:-0.2063904pt" version="1.1" viewbox="-0.0498162 -5.96091 6.6501 6.1673" width="6.6501pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M495 86L479 114C446 82 419 66 409 66C401 66 401 72 406 97C420 166 436 231 453 297C489 435 454 448 428 448C406 448 384 439 354 422C305 394 222 327 161 247H159L183 345C200 415 194 448 173 448C143 448 82 410 23 351L38 325C64 349 95 371 105 371C111 371 116 365 109 336L25 -4L31 -12C50 -4 77 3 107 9C119 69 132 122 145 168C197 254 321 381 370 381C387 381 393 374 378 305L329 95C309 17 320 -12 345 -12C372 -12 430 19 495 86Z"></path></g></svg> represents the number of crystalline molecules, and <svg height="8.8423pt" id="M120" style="vertical-align:-0.2064009pt" version="1.1" viewbox="-0.0498162 -8.6359 17.3892 8.8423" width="17.3892pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M600 0V24L339 665L311 657L43 24V0H600ZM497 50H107L303 539L497 50Z"></path></g><g transform="matrix(.013,0,0,-0.013,8.327,0)"><path d="M673 297H417L411 270C517 261 522 258 506 183L487 92C476 38 428 19 360 19C207 19 123 132 123 287C123 472 243 631 441 631C557 631 617 583 617 469L647 472C650 545 655 604 658 632C625 643 554 666 467 666C201 666 23 502 23 278C23 90 156 -16 339 -16C410 -16 501 6 569 24C566 43 567 70 573 101L589 183C604 259 607 262 667 271L673 297Z"></path></g></svg> is the Gibbs free energy change during nucleation. CNT is a one-step mechanism characterized by a single high free energy barrier (orange). Prenucleation is a two-step pathway with the metastable point representing the liquid precursor (blue). Spinodal decompensation proceeds in a barrierless fashion (yellow).</div>

Geofluids

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Figure 8

Figure 8: Ab Initio Molecular Dynamics Simulations and Vibrational Frequency Calculations of Species in Liquid-Liquid Phase Separated MgSO<sub>4</sub> Solution at 543 K 

Figure 8 | Ab Initio Molecular Dynamics Simulations and Vibrational Frequency Calculations of Species in Liquid-Liquid Phase Separated MgSO4 Solution at 543 K 